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Ideal Gas Law - Practice Questions (39)

Question 1: 1. The ideal gas equation of state $\mathrm { pV } = \mathrm { nRT }$ is an equation of state that d...

1. The ideal gas equation of state $\mathrm { pV } = \mathrm { nRT }$ is an equation of state that describes the relationship between the amount of substance of an ideal gas and its volume, partial pressure, and temperature. The molar gas constant $R$ can be determined by the experimental setup shown in the figure. During the experiment, an aluminum sheet is polished and weighed, and then copper wire is wrapped around it and placed at the mouth of the reaction tube, and a sufficient amount of dilute sulfuric acid is added to the reaction tube. After taking the starting reading of the gas measuring tube, move the reaction tube so that the aluminum piece slides into the dilute sulfuric acid. The following statement is not correct ( ) ![](/images/questions/ideal-gas-law/image-001.jpg)

  • A. A. The gas measuring tube of the simple gas measuring device can be replaced by an alkaline buret.
  • B. B. The purpose of wrapping a piece of aluminum with copper wire is to speed up the rate of the reaction
  • C. C. Dilute nitric acid should not be used in place of dilute sulfuric acid
  • D. D. The gas measuring tube should be read as soon as the solution in the reaction tube does not produce any obvious bubbles

Answer: D

Solution: A. The gas measuring tube can be replaced by an alkaline buret, A is correct; B. Copper wire wrapped around an aluminum sheet to form a primary cell, can speed up the reaction rate, B correct; C. Dilute nitric acid will react with the copper wire to generate NO, affecting the determination of the volume of hydrogen, so you can not use dilute nitric acid instead of dilute sulfuric acid, C is correct; D. reaction tube solution without obvious bubbles, should wait for the device to cool down, move up and down the level tube to the level tube and the level of the gas tube, and then read, D error;

Question 2: 2. At a temperature of $\mathrm { T } ^ { \circ } \mathrm { C }$, a sufficient amount of activated c...

2. At a temperature of $\mathrm { T } ^ { \circ } \mathrm { C }$, a sufficient amount of activated carbon and $1 \mathrm { molNO } _ { 2 }$ are added to closed containers of unequal volume, and the following reaction occurs: $2 \mathrm { C } ( \mathrm { S } ) + 2 \mathrm { NO } _ { 2 } ( \mathrm {~g} ) = \mathrm { N } _ { 2 } ( \mathrm {~g} ) + 2 \mathrm { CO } _ { 2 } ( \mathrm {~g} )$. At the same reaction time, the conversion rate of $\mathrm { NO } _ { 2 }$ in each container is measured as a function of the volume of the container as shown in the graph ($\mathrm { V } _ { 1 } < \mathrm { V } _ { 2 } < \mathrm { V } _ { 3 }$ ). Known: The ideal gas equation of state is $\mathrm { pV } = \mathrm { nRT }$. The following statement is false ( ) ![](/images/questions/ideal-gas-law/image-002.jpg) Volume of the container / L

  • A. A. At $T ^ { \circ } \mathrm { C }$, the equilibrium constant of the reaction at $a$ is $\frac { 4 } { 45 V _ { 1 } }$
  • B. B. According to the ideal gas equation, the pressure inside the container: $\mathrm { Pa } : \mathrm { Pb } = 6 : 7$
  • C. C. $T ^ { \circ } \mathrm { C }$ when point b is in chemical equilibrium, point c is not in chemical equilibrium
  • D. D. Pressurize the container at point c to reduce the volume of the container, then at this point $\mathrm { v } _ { \text {正 } } > \mathrm { v }$ inverse

Answer: B

Solution: A. Based on the data at point a, the reaction reaches equilibrium at point a. The $\mathrm { NO } _ { 2 }$ conversion rate is $40 \%$ and the reaction triplet at point a is: | | $2 \mathrm { C } ( \mathrm { s } ) + 2 \mathrm { NO } _ { 2 } ( \mathrm {~g} )$ | $= \mathrm { N } _ { 2 } ( \mathrm {~g} )$ | $+ 2 \mathrm { CO } _ { 2 } ( \mathrm {~g} )$ | | | :--- | :---: | :---: | :---: | :---: | :---: | | Starting amount $( \mathrm { mol } )$ | | 1 | 0 | 0 | | change amount $( \mathrm { mol } )$ | | 0.4 | 0.2 | 0.4 | | Equilibrium $( \mathrm { mol } )$ | | 0.6 | 0.2 | 0.4 | At an equilibrium concentration of each substance of $\mathrm { c } \left( \mathrm { NO } _ { 2 } \right) = \frac { 0.6 } { \mathrm {~V} _ { 1 } } \mathrm { mo } / \mathrm { L } , \mathrm { c } \left( \mathrm { N } _ { 2 } \right) = \frac { 0.2 } { \mathrm {~V} _ { 1 } } \mathrm {~mol} / \mathrm { L } , \mathrm { c } \left( \mathrm { CO } _ { 2 } \right) = \frac { 0.4 } { \mathrm {~V} _ { 1 } } \mathrm {~mol} / \mathrm { L } , \mathrm { T } ^ { \circ } \mathrm { C }$, the reaction The equilibrium constant of the reaction is $= \frac { \mathrm { c } \left( \mathrm { N } _ { 2 } \right) \cdot \mathrm { c } ^ { 2 } \left( \mathrm { CO } _ { 2 } \right) } { \mathrm { c } ^ { 2 } \left( \mathrm { NO } _ { 2 } \right) } = \frac { \frac { 0.2 } { \mathrm {~V} _ { 1 } } \times \left( \frac { 0.4 } { \mathrm {~V} _ { 1 } } \right) ^ { 2 } } { \left( \frac { 0.6 } { \mathrm {~V} _ { 1 } } \right) ^ { 2 } } = \frac { 4 } { 45 \mathrm {~V} _ { 1 } }$ at an equilibrium concentration of $\mathrm { c } \left( \mathrm { NO } _ { 2 } \right) = \frac { 0.6 } { \mathrm {~V} _ { 1 } } \mathrm { mo } / \mathrm { L } , \mathrm { c } \left( \mathrm { N } _ { 2 } \right) = \frac { 0.2 } { \mathrm {~V} _ { 1 } } \mathrm {~mol} / \mathrm { L } , \mathrm { c } \left( \mathrm { CO } _ { 2 } \right) = \frac { 0.4 } { \mathrm {~V} _ { 1 } } \mathrm {~mol} / \mathrm { L } , \mathrm { T } ^ { \circ } \mathrm { C }$; B. According to the data in B, the amount of gas in the container at point a is $1.2 \mathrm {~mol} ; \mathrm { b }$, and the reaction is trivial: | | $2 \mathrm { C } ( \mathrm { s } )$ | $+ 2 \mathrm { NO } _ { 2 } ( \mathrm {~g} )$ | $=$ | $\mathrm { N } _ { 2 } ( \mathrm {~g} )$ | :--- | :---: | :---: | :---: | :---: | :---: | | Starting amount $( \mathrm { mol } )$ | | 1 | 0 | $2 \mathrm { CO } _ { 2 } ( \mathrm {~g} )$ | | change amount $( \mathrm { mol } )$ | | 0.8 | 0.4 | 0.8 | | Equilibrium $( \mathrm { mol } )$ | | 0.2 | 0.4 | 0.8 | According to the reaction triplet at point a, the triplet at point b and $\mathrm { pV } = \mathrm { nRT }$ in option A, $\mathrm { P } _ { \mathrm { a } } \mathrm { V } _ { 1 } = 1.2 \mathrm { RT } , ~ \mathrm { P } _ { \mathrm { b } } \mathrm { V } _ { 2 } = 1.4 \mathrm { RT }$ can be found, $\mathrm { P } _ { \mathrm { a } } \mathrm { V } _ { 1 } = 1.2 \mathrm { RT } , ~ \mathrm { P } _ { \mathrm { b } } \mathrm { V } _ { 2 } = 1.4 \mathrm { RT }$, and because of the $V _ { 2 } > V _ { 1 }$, the pressure inside the container: $\mathrm { Pa } : \mathrm { Pb } > 6 : 7$, so B is wrong; C. The conversion rate of $\mathrm { NO } _ { 2 }$ is the highest at point b in the figure, then the equilibrium is reached at point b at the temperature of $\mathrm { T } ^ { \circ } \mathrm { C }$, and the volume of the corresponding container on the ab curve increases gradually, and the starting concentration of $\mathrm { NO } _ { 2 }$ decreases gradually, but the concentration is greater than that at point b, so it is wrong. As the volume of the corresponding container on the ab curve gradually increases, the starting concentration of $\mathrm { NO } _ { 2 }$ gradually decreases, but the concentration is greater than that at point b. The greater the concentration of $\mathrm { NO } _ { 2 }$, the greater the reaction rate, and the shorter the time to reach equilibrium, so the reactions on the ab curve reach equilibrium, and the positive direction of the reaction is the reaction with the increase of the gas volume. As the volume of the container increases, the starting concentration of $\mathrm { NO } _ { 2 }$ decreases, the reaction rate slows down, and the time to reach equilibrium is prolonged, so the reaction on the bc curve has not reached equilibrium, C is correct; D. In the same reaction time, the container volume corresponding to point c is the largest and the pressure is the smallest, the chemical reaction rate is slower, so the conversion rate of nitrogen dioxide is smaller, pressurize the container at point c and reduce the container volume, then the chemical reaction rate is accelerated, and the reaction is carried out in the direction of the positive reaction, at this time $v$ (inverse) $< v$ (reverse). 30]] (positive), D is correct.

Question 3: 3. If the volumes of two gases at the same temperature and pressure are not the same, speculate on t...

3. If the volumes of two gases at the same temperature and pressure are not the same, speculate on the main reason for this ()

  • A. A. Gases have different molecule sizes
  • B. B. The gases have different amounts of substance
  • C. C. Gas molecules have different chemical properties
  • D. D. The average distance between gas molecules is different

Answer: B

Solution: For the gas, the distance between the particles is much larger than the diameter of the particles, the mass of the particles, the volume of the gas depends mainly on the number of gas particles and the size of the distance between the gas particles; the distance between the gas particles at the same temperature and pressure is equal, and the molar volume of the gas is the same at the same temperature and pressure, by $V = n V _ { m } = \frac { N } { N _ { \mathrm { A } } } V _ { m }$, the volume of two gases if they are not the same, then the volume of gas is different. The number of particles is different, that is, the amount of substance of the gases is different, so choose B.

Question 4: 4. The following narratives are correct

4. The following narratives are correct

  • A. A. At a certain temperature and pressure, the volume of a gas is determined by the size of its molecules
  • B. B. At a certain temperature and pressure, the volume of a gas is determined by the amount of its substance
  • C. C. The molar volume of a gas is the volume occupied by 1 mol of any gas 22.4 L
  • D. D. Different gases that are not equal in volume must not contain the same number of molecules

Answer: B

Solution: A. From $\mathrm { PV } = \mathrm { nRT }$, it can be known that the volume of a gas is directly proportional to the amount of substance when the temperature and pressure are certain; when the number of molecules is the same, the size of the volume of the gas is mainly determined by the distance between the molecules of the gas, not the size of the volume of the molecules themselves, A is wrong; B. According to the analysis in A, B is correct; C, only the molar volume of gas under standard conditions is approximated as $22.4 \mathrm {~L} / \mathrm { mol }$, C error; D, different gases may contain equal numbers of molecules if their volumes are not equal but their amounts of substance may be equal, D is wrong ; Answer choice B.

Question 5: 5. Let $\mathrm { N } _ { \mathrm { A } }$ be the value of Avogadro's constant. If ag the number of ...

5. Let $\mathrm { N } _ { \mathrm { A } }$ be the value of Avogadro's constant. If ag the number of molecules of a gas is p, then bg the volume V(L) of the gas in standard form is about

  • A. A. $\frac { 22.4 \mathrm { bp } } { \mathrm { aN } _ { \mathrm { A } } }$
  • B. B. $\frac { 22.4 \mathrm { ab } } { \mathrm { pN } _ { \mathrm { A } } }$
  • C. C. $\frac { 22.4 \mathrm {~N} _ { \mathrm { A } } \mathrm { b } } { \mathrm { a } }$
  • D. D. $\frac { 22.4 a p } { b N _ { A } }$

Answer: A

Solution: Since ag the number of molecules of the gas is p, then bg the number of molecules of the gas is: $\frac { \mathrm { bp } } { \mathrm { a } }$, then bg the amount of the gas is: $n = \frac { N } { N _ { A } } = \frac { b p } { a N _ { A } } m o l$, and the volume in standard form is about $V = n N _ { A } = \frac { 22.4 b p } { a N _ { A } } L$, A is correct;

Question 6: 6. At room temperature and pressure, blow up four balloons with equal mass of $\mathrm { CH } _ { 4 ...

6. At room temperature and pressure, blow up four balloons with equal mass of $\mathrm { CH } _ { 4 } , \mathrm { CO } _ { 2 } , \mathrm { O } _ { 2 } , \mathrm { SO } _ { 2 }$, of which the gas is $\mathrm { CH } _ { 4 }$. | | | | | | | | :--- | :--- | :--- | :--- | :--- | | | | | | | | | | | | | | |

  • A. A. A
  • B. B. B
  • C. C. C
  • D. D. D

Answer: D

Solution: Under the same conditions, the molar volumes of gases are equal. According to $V = n V _ { m } = \frac { m } { M }$, the volume of a gas is inversely proportional to the molar mass of the gas when it has the same mass, and the molar mass is $16 \mathrm {~g} / \mathrm { mol } , 44 \mathrm {~g} / \mathrm { mol } , 32 \mathrm {~g} / \mathrm { mol } , 64 \mathrm {~g} / \mathrm { mol }$, and according to the molar mass, the volume of $\mathrm { CH } _ { 4 }$ is in the first place, that is, D is consistent with the meaning of the question. The answer is D.

Question 7: 7. At the same temperature and pressure, $\mathrm { H } _ { 2 }$ in container A and $\mathrm { NH } ...

7. At the same temperature and pressure, $\mathrm { H } _ { 2 }$ in container A and $\mathrm { NH } _ { 3 }$ in container B contain equal numbers of atoms, then the ratio of the volumes of A and B is ( ).

  • A. A. $2 : 1$
  • B. B. $1 : 2$
  • C. C. 2:3
  • D. D. $1 : 1$

Answer: A

Solution: Under the same conditions, the gases $\mathrm { V } _ { \mathrm { m } }$ are equal, and the ratio of the number of molecules is known from the number of atoms they contain 2:1, from $\mathrm { n } = \frac { V } { V _ { m } } = \frac { N } { N _ { A } }$ we can see that the ratio of the number of molecules of a gas is equal to the ratio of its volume, then the volume ratio is $2 : 1$, so choose A.

Question 8: 8. The number of molecules in 13 g of a gas at standard conditions is equal to the number of molecul...

8. The number of molecules in 13 g of a gas at standard conditions is equal to the number of molecules in 14 g of CO, and the density of this gas is (

  • A. A. $1.25 \mathrm {~g} \cdot \mathrm {~L} ^ { - 1 }$
  • B. B. $2.32 \mathrm {~g} \cdot \mathrm {~L} ^ { - 1 }$
  • C. C. $1.65 \mathrm {~g} \cdot \mathrm {~L} ^ { - 1 }$
  • D. D. $1.16 \mathrm {~g} \cdot \mathrm {~L} ^ { - 1 }$

Answer: D

Solution: The amount of substance of 14 g of CO is $\frac { 14 \mathrm {~g} } { 28 \mathrm {~g} / \mathrm { mol } } = 0.5 \mathrm {~mol}$, so the amount of substance of 13 g of this gas is 0.5 mol, and the volume of this gas at standard conditions is $0.5 \mathrm {~mol} \times 22.4 \mathrm {~L} / \mathrm { mol } = 11.2 \mathrm {~L}$. The volume of the gas at standard conditions is $0.5 \mathrm {~mol} \times 22.4 \mathrm {~L} / \mathrm { mol } = 11.2 \mathrm {~L}$. Therefore, the density of the gas at standard conditions is $\frac { 13 \mathrm {~g} } { 11.2 \mathrm {~L} } = 1.16 \mathrm {~g} / \mathrm { L }$. Therefore, choose D. Alternatively, 14 g of CO has an amount of matter of 0.5 mol, so 13 g of a gas has an amount of matter of $0.5 \mathrm {~mol} , ~ \mathrm { M } = \frac { 13 \mathrm {~g} } { 0.5 \mathrm {~mol} } = 26 \mathrm {~g} / \mathrm { mol } , ~ \rho = \frac { 26 \mathrm {~g} / \mathrm { mol } } { 22.4 \mathrm {~L} / \mathrm { mol } } = 1.16 \mathrm {~g} / \mathrm { L }$. ## 9. D [Knowledge Points]Gas substance and NA-related deduction, according to the $n = m / M$ of the relevant calculations [Detailed] According to the formula: $\mathrm { n } = \frac { \mathrm { m } } { \mathrm { M } } , ~ \mathrm { n } = \frac { V } { V _ { m } }$ can be withdrawn from the relationship: $\frac { \mathrm { m } } { \mathrm { M } } = \frac { V } { V _ { m } }$, substitution of the calculation of the molar mass is: , the units of A and C are wrong, and the value of B is wrong, so the answer to this question is D.

Question 9: 9. A gas has a mass of 14.2 g and a volume of 4.48 L (standard conditions), the molar mass of the ga...

9. A gas has a mass of 14.2 g and a volume of 4.48 L (standard conditions), the molar mass of the gas is

  • A. A. 71 g
  • B. B. $28.4 \mathrm {~g} \cdot \mathrm {~mol} ^ { - 1 }$
  • C. C. 71
  • D. D. $71 \mathrm {~g} \cdot \mathrm {~mol} ^ { - 1 }$

Answer: D

Solution:

Question 10: 10. Comparing carbon monoxide and carbon dioxide, which have equal amounts of matter, the following ...

10. Comparing carbon monoxide and carbon dioxide, which have equal amounts of matter, the following statements are correct $\_\_\_\_$ (1) The ratio of the number of molecules contained is $1 : 1$ (2) The ratio of the number of oxygen atoms contained is $1 : 2$ (3) The ratio of the total number of atoms contained is $2 : 3$ (4) The ratio of the number of carbon atoms contained is $1 : 1$ (5) The ratio of the number of electrons contained is $7 : 11$

  • A. A. (1) (2)
  • B. B. (2) (3)
  • C. C. (4) (5)
  • D. D. (1) (2) (3) (4) (5)

Answer: D

Solution: FORMULA_2]], so (2) is correct; the ratio of the amount of matter (or mass) of carbon atoms is $1 : 1$, and the ratio of the total number of atoms contained is $2 : 3$, so (3) is correct; the ratio of the number of electrons contained is $14 : 22 = 7 : 11$, so (4) is is correct. Therefore, (1) (2) (3) (4) (5) are all correct, so D meets the meaning of the question; Answer:D. [点睛] According to Avogadro's law to analyze. That is, the ratio of the amount of substance at the same temperature and pressure is equal to the ratio of the number of molecules. 11 . [Knowledge Points]The effect of pressure on the movement of chemical equilibrium, the effect of activation energy on the rate of reaction, the composite criterion, the effect of temperature on the rate of chemical equilibrium. ## The effect of temperature on the movement of chemical equilibrium [Detailed Explanation]A..$\Delta H = E _ { \text {正 } } - E _ { \text {逆 } }$, $\Delta H = - 34585 - 26.4 T$ in the question, is negative and becomes more negative with increasing temperature, which means $E _ { \text {正 } } < E _ { \text {逆 } } , \mathrm { A }$ is wrong; B. When $\mathrm { N } _ { 2 }$ is charged at constant temperature and constant capacity, the total pressure increases but the partial pressures of the reactants remain unchanged, and the equilibrium does not move, B is wrong; C. Substitute $\Delta \mathrm { G } = \Delta H - T \Delta S$ into the data to get $\Delta S = - 71.59 - 26.4 \ln T$, $\ln T$ increases when the temperature T increases, $\Delta S$ is smaller, $\Delta S$ decreases when the temperature increases. C is correct; D. The reaction, $\Delta H < 0$, is exothermic, and increasing the temperature increases the rate of the inverse of the exothermic reaction even more, $\Delta v _ { \text {逆 } } > \Delta v _ { \text {正 } }$, D is incorrect;

Question 11: 11. At a given pressure, the hydration of ethylene is: $\mathrm { C } _ { 2 } \mathrm { H } _ { 4 } ...

11. At a given pressure, the hydration of ethylene is: $\mathrm { C } _ { 2 } \mathrm { H } _ { 4 } ( \mathrm {~g} ) + \mathrm { H } _ { 2 } \mathrm { O } ( \mathrm { g } ) \rightleftharpoons \mathrm { C } _ { 2 } \mathrm { H } _ { 5 } \mathrm { OH } ( \mathrm { g } )$ Known: $\Delta \mathrm { H } ( \mathrm { J } / \mathrm { mol } ) = - 34585 - 26.4 \mathrm {~T}$ $\Delta \mathrm { G } ( \mathrm { J } / \mathrm { mol } ) = - 34585 + 26.4 \mathrm {~T} \cdot \ln \mathrm {~T} + 45.19 \mathrm {~T}$ The gases are all considered ideal gases and the following statements are correct

  • A. A. Activation energy of the reaction: $\mathrm { E } _ { \text {正 } } > \mathrm { E } _ { \text {逆 } }$
  • B. B. Constant temperature and constant capacity is charged to ${ } ^ { \mathrm { N } _ { 2 } }$ and the equilibrium is shifted to the left.
  • C. C. ${ } ^ { \Delta } \mathrm { S } _ { \text {随温度升高而降低 } }$
  • D. D. After equilibration, increase the temperature, $\Delta \mathrm { v } _ { \text {正 } } > \Delta \mathrm { v } _ { \text {逆 } }$

Answer: C

Solution:

Question 12: 12. $\mathrm { N } _ { \mathrm { A } }$ denotes Avogadro's constant, if the number of molecules in 4...

12. $\mathrm { N } _ { \mathrm { A } }$ denotes Avogadro's constant, if the number of molecules in 40 g of a gas is $2 \mathrm {~N} _ { \mathrm { A } }$, then the volume of 25 g of the gas at standard conditions is ( )

  • A. A. 22.4 L
  • B. B. 28 L
  • C. C. 33.6 L
  • D. D. 40 L

Answer: B

Solution: The number of molecules contained in 40 g of a gas is $2 \mathrm {~N} _ { \mathrm { A } }$ and the molar mass of the gas is $20 \mathrm {~g} / \mathrm { mol } , 25 \mathrm {~g}$ The amount of gas $= \frac { 25 \mathrm {~g} } { 25 \mathrm {~g} / \mathrm { mol } } = 1.25 \mathrm {~mol}$ and the volume $= 1.25 \mathrm {~mol} \times 22.4 \mathrm {~L} / \mathrm { mol } = 28 \mathrm {~L}$;

Question 13: 13. mg A gas of a diatomic molecule has a volume of $V _ { 1 } \mathrm {~L}$ at standard conditions ...

13. mg A gas of a diatomic molecule has a volume of $V _ { 1 } \mathrm {~L}$ at standard conditions and a molar mass of $\mathrm { Mg } / \mathrm { mol }$, and is dissolved in water (with which the gas does not react) to give a solution with a volume of ${ } ^ { V 2 } \mathrm {~L}$, ${ } ^ { N }$ represents the value of Avogadro's constant. FORMULA_3]] represents the value of Avogadro's constant, then the following is wrong ( )

  • A. A. The molar mass of this gas molecule is $\frac { 22.4 m } { V _ { 1 } } \mathrm {~g} / \mathrm { mol }$
  • B. B. The number of atoms contained in this gas molecule is $\frac { N _ { \mathrm { A } } V _ { 1 } } { 22.4 }$
  • C. C. The gas dissolves in water to give a solution with a material concentration of $\frac { m } { M V _ { 2 } } \mathrm {~mol} / \mathrm { L }$
  • D. D. The gas dissolves in water to give a solution with a material concentration of $\frac { V _ { 1 } } { 22.4 V _ { 2 } } \mathrm {~mol} / \mathrm { L }$

Answer: B

Solution: A. $\mathrm { n } = \frac { V _ { 1 } } { 22.4 } \mathrm {~mol} , ~ M = \frac { \mathrm { mg } } { \frac { V _ { 1 } } { 22.4 } \mathrm {~mol} } = \frac { 22.4 \mathrm {~m} } { V _ { 1 } } \mathrm {~g} / \mathrm { mol }$, so A is correct; B. $\mathrm { n } = \frac { V _ { 1 } } { 22.4 } \mathrm {~mol}$ , since it is a diatomic molecule, the number of atoms contained in the gas molecule is $\frac { N _ { \mathrm { A } } V _ { 1 } } { 11.2 }$ , so B is wrong ; $\mathrm { C } . \mathrm { n } = \mathrm { m } \div \mathrm { M }$ , then the concentration of the substance of the solution obtained when the gas is dissolved in water is $\frac { m } { M V _ { 2 } } \mathrm {~mol} / \mathrm { L }$ , so C is correct; $\mathrm { D } \cdot \mathrm { n } = \frac { V _ { 1 } } { 22.4 } \mathrm {~mol}$, the concentration of the substance of the solution obtained after the gas is dissolved in water is $\frac { V _ { 1 } } { 22.4 V _ { 2 } } \mathrm {~mol} / \mathrm { L }$, so D is correct.

Question 14: 14. Scientists have just discovered that the mass of an atom of a certain element is mg, the mass of...

14. Scientists have just discovered that the mass of an atom of a certain element is mg, the mass of an atom of ${ } ^ { 12 } \mathrm { C }$ is ng, $\mathrm { N } _ { \mathrm { A } }$ is the value of Avogadro's constant, and the following statements are not correct ()

  • A. A. The molar mass of this atom is $\mathrm { mN } _ { \mathrm { A } } \mathrm { g } / \mathrm { mol }$
  • B. B. The relative atomic mass of this atom is $\frac { 12 n } { m }$
  • C. C. Wg The atom contains $\frac { \mathrm { W } } { \mathrm { m } }$ atoms of this type.
  • D. D. From known information : $N _ { A } = \frac { 12 } { n } \mathrm {~mol} ^ { - 1 }$

Answer: B

Solution:

Question 15: 15. Let $\mathrm { N } _ { \mathrm { A } }$ be the value of Avogadro's constant. If ag a gas contain...

15. Let $\mathrm { N } _ { \mathrm { A } }$ be the value of Avogadro's constant. If ag a gas contains b molecules, then cg the volume of the gas at standard conditions is ( ).

  • A. A. $\frac { 22.4 b c } { a N _ { A } L }$
  • B. B. $\frac { 22.4 a b } { \mathrm { cN } _ { \mathrm { A } } } \mathrm { L }$
  • C. C. $\frac { 22.4 \mathrm { ac } } { \mathrm { bN } _ { \mathrm { A } } } \mathrm { L }$
  • D. D. $\frac { 22.4 b } { \mathrm { cN } _ { \mathrm { A } } } \mathrm { L }$

Answer: A

Solution: ag The number of molecules contained in a gas is b, then cg The number of molecules contained in the gas is $\frac { \mathrm { bc } } { \mathrm { a } } , \mathrm { cg }$ The amount of material in the gas is $\frac { \mathrm { bc } } { \mathrm { a } \times \mathrm { N } _ { \mathrm { A } } } \mathrm { mol }$ and the volume at standard conditions is $\frac { \mathrm { bc } } { \mathrm { a } \times \mathrm { N } _ { \mathrm { A } } } \mathrm { mol } \times 22.4 \mathrm {~L} / \mathrm { mol } = \frac { 22.4 \mathrm { bc } } { \mathrm { aN } _ { \mathrm { A } } } \mathrm { L }$.

Question 16: 16. Nitrogen trichloride can be used for bleaching and the reaction: $2 \mathrm { NCl } _ { 3 } + 3 ...

16. Nitrogen trichloride can be used for bleaching and the reaction: $2 \mathrm { NCl } _ { 3 } + 3 \mathrm { H } _ { 2 } \mathrm { O } = 3 \mathrm { HCl } + 3 \mathrm { HClO } + \mathrm { N } _ { 2 } \uparrow$ occurs when it is used. Let $N _ { \mathrm { A } }$ be the value of Avogadro's constant, the following statement is not correct ()

  • A. A. The number of lone electron pairs in ${ } ^ { 1 } \mathrm { molNCl } _ { 3 }$ is $N _ { \mathrm { A } }$
  • B. B. Standard condition, $3.36 \mathrm { LHCl } _ { \text {中含有质子数为 } } 2.7 N _ { \mathrm { A } }$
  • C. C. The number of ${ } ^ { 1 \mathrm { LpH } = 1 }$'s $\mathrm { HClO } _ { \text {溶液中 } } \mathrm { ClO } ^ { - }$ is less than $0.1 N _ { \mathrm { A } }$
  • D. D. The number of electrons transferred to produce $14 \mathrm { gN } _ { 2 }$ reactions at room temperature and pressure is $3 N _ { \mathrm { A } }$

Answer: A

Solution: A. Each Cl in $\mathrm { NCl } _ { 3 }$ contains 3 lone pairs of electrons, and each N atom contains 1 lone pair of electrons, so the number of lone pairs of electrons in $\operatorname { lmolNCl } _ { 3 }$ is ${ } ^ { 10 N _ { \mathrm { A } } }$, and so A is wrong; B. Under standard conditions, 3.36L of HCl is $0.15 \mathrm {~mol} , 1$ molecules of HCl containing 18 protons, and 0.15 mol of HCl contains 18 protons. The number of protons in 0.15 mol of HCl is $2.7 N _ { \mathrm { A } }$, so B is correct; C. The number of $\mathrm { HClO } _ { \text {溶液中存在电荷守恒:} } \mathrm { c } \left( \mathrm { ClO } ^ { - } \right) + \mathrm { c } \left( \mathrm { OH } ^ { - } \right) = \mathrm { c } \left( \mathrm { H } ^ { + } \right) , \mathrm { c } \left( \mathrm { H } ^ { + } \right) = 0.1 \mathrm {~mol} / \mathrm { L }$ of $1 \mathrm { LpH } = 1$ is ${ } ^ { 0.1 N _ { \mathrm { A } } }$, and the sum of the number of $\mathrm { ClO } ^ { - } , \mathrm { OH } ^ { - }$ is ${ } ^ { 0.1 N _ { \mathrm { A } } } , \mathrm { ClO } ^ { - }$ is less than ${ } ^ { 0.1 N _ { \mathrm { A } } }$. FORMULA_10]], so C is correct; D. From the reaction can be generated 1 mol nitrogen transfer 6 mol electrons, then generated ${ } ^ { 14 \mathrm { gN } _ { 2 } }$ that is 0.5 mol, the reaction of the number of electrons transferred to ${ } ^ { 3 N _ { \mathrm { A } } }$, so D is correct;

Question 17: 17. The following narratives are correct ( )

17. The following narratives are correct ( )

  • A. A. 1 mol of any substance contains $6.02 \times 10 ^ { 23 }$ ions
  • B. B. $0.012 \mathrm {~kg} ^ { 12 } \mathrm { C }$ contains about $6.02 \times 10 ^ { 23 }$ carbon molecules
  • C. C. 1 mol of water contains 2 mol of hydrogen and 1 mol of oxygen.
  • D. D. 1 mol Ne contains $6.02 \times 10 ^ { 24 }$ electrons

Answer: D

Solution: A. There are atoms, molecules, and ions that make up matter, so you can't say that 1 mol of any substance contains $6.02 \times 10 ^ { 23 }$ ions, so A is wrong; B. $0.012 \mathrm {~kg} ^ { 12 } \mathrm { C }$ contains about $6.02 \times 10 ^ { 23 }$ carbon atoms and no carbon molecules; C. $\mathrm { H } _ { 2 } \mathrm { O }$ is made up of molecules, and 1 mol of water molecules contains 2 mol of hydrogen atoms and 1 mol of oxygen atoms, so it is necessary to specify what kind of particles should be used when using moles, and the title does not specify the kind of particles; D. Ne is the 10th element, and 1 Ne atom contains 10 electrons. Since Ne is a monatomic molecule, 1 mol of Ne atoms contains $6.02 \times 10 ^ { 24 }$ electrons, D is correct; D is correct.

Question 18: 18. With 0.5 mol of HCl available, the following statements are correct ()

18. With 0.5 mol of HCl available, the following statements are correct ()

  • A. A. The number of molecules contained is $6.02 \times 10 ^ { 23 }$
  • B. B. Mass 9 g
  • C. C. The volume at room temperature is 11.2 L
  • D. D. Dissolve in water to make a 2 L solution containing $\mathrm { H } ^ { + }$ at a concentration of $0.25 \mathrm {~mol} \cdot \mathrm {~L} ^ { - 1 }$

Answer: D

Solution: A. The number of molecules contained in 0.5 molHCl is $3.01 \times 10 ^ { 23 }$, so A is wrong; B. The mass is $0.5 \mathrm {~mol} \times 36.5 \mathrm {~g} / \mathrm { mol } = 18.25 \mathrm {~g}$, so B is wrong; C. The volume at standard condition is 11.2L, so C is wrong; D. Dissolve in water to form a 2 L solution containing $\mathrm { H } ^ { + }$ at a concentration of $\frac { 0.5 \mathrm {~mol} } { 2 \mathrm {~L} } = 0.25 \mathrm {~mol} \cdot \mathrm {~L} ^ { - 1 }$, so D is correct.

Question 19: 19. The following statement about $1 \mathrm { molNH } _ { 3 }$ is correct ($\mathrm { N } _ { \math...

19. The following statement about $1 \mathrm { molNH } _ { 3 }$ is correct ($\mathrm { N } _ { \mathrm { A } }$ represents the value of Avogadro's constant) ()

  • A. A. $\mathrm { NH } _ { 3 }$ has a molar mass of 17 g
  • B. B. The number of contained electrons is $10 \mathrm {~N} _ { \mathrm { A } }$
  • C. C. The volume at room temperature and pressure is about 22.4 L
  • D. D. Dissolved in 1 L of water, the resulting solution has a material concentration of $1 \mathrm {~mol} \cdot \mathrm {~L} ^ { - 1 }$

Answer: B

Solution: A. The molar mass of an ammonia molecule is $17 \mathrm {~g} / \mathrm { mol }$, and A is wrong; B. 1 mol of ammonia contains 10 mol of electrons, and the number of electrons is $10 \mathrm {~N} _ { \mathrm { A } }$, which is correct; C. At standard conditions, the volume of 1 mol of ammonia is about 22.4 L, and the molar volume of the gas at room temperature and pressure is greater than $22.4 /$ Lmol, so the volume of 1 mol of ammonia is greater than 22.4 L, and C is wrong; D. Dissolved in 1 L of water, the total volume of the solution will change, then the concentration of the solution is not $1 \mathrm {~mol} / \mathrm { L }$, D error; Answer choice B.

Question 20: 20. The following narratives are correct

20. The following narratives are correct

  • A. A. $2 \mathrm { gH } _ { 2 }$ contains 2 mol of atoms.
  • B. B. The molar mass of nitric acid is ${ } ^ { 63 \mathrm {~g} }$
  • C. C. The mass of 1 molCO is 28 g
  • D. D. The molar mass of iron is equal to the relative atomic mass of iron atoms

Answer: C

Solution: A. 2 g of hydrogen has a substance of 1 mol, contains 2 mol of H atoms, and has a number of atoms of $2 \mathrm {~N} _ { \mathrm { A } }$, A is wrong; B. The unit of molar mass is $\mathrm { g } / \mathrm { mol }$, and the molar mass of nitric acid is $63 \mathrm {~g} / \mathrm { mol }$; C. The molar mass of CO is $28 \mathrm {~g} / \mathrm { mol }$, so the mass of 1 mol of CO is 28 g. C is correct; D. The unit of molar mass is $\mathrm { g } / \mathrm { mol }$, and the relative atomic mass has no unit, the molar mass of iron is numerically equal to the relative atomic mass of iron atoms, and the units are different, so the meaning is not the same, D is wrong;

Question 21: 21. The following statement is correct ( $\mathrm { N } _ { \mathrm { A } }$ indicates the value of ...

21. The following statement is correct ( $\mathrm { N } _ { \mathrm { A } }$ indicates the value of Avogadro's constant) ()

  • A. A. 1 mol methyl contains $10 \mathrm {~N} _ { \mathrm { A } }$ electrons
  • B. B. Under certain conditions, the number of molecules of $\mathrm { O } _ { 2 }$ consumed in the complete combustion of 2.6 g of benzene and acetylene mixture is $0.25 \mathrm {~N} _ { \mathrm { A } }$.
  • C. C. The number of molecules in 11.2 L of trichloromethane under standard conditions is $0.5 \mathrm {~N} _ { \mathrm { A } }$
  • D. D. $15 \mathrm { gC } _ { 2 } \mathrm { H } _ { 6 }$ contains the number of covalent bonds as $3 \mathrm {~N} _ { \mathrm { A } }$

Answer: B

Solution: A. Methyl contains 9 electrons, so 1 mol of methyl contains $9 \mathrm {~N} _ { \mathrm { A } }$ electrons, so A is wrong; B. The simplest formulas of benzene and acetylene are both CH, so the amount of CH contained in 2.6 g of the mixture is 0.2 mol, and it contains $0.2 \mathrm {~N} _ { \mathrm { A } }$ carbon atoms, so B is correct; C. Trichloromethane is liquid under standard conditions, so the amount of substance and the number of molecules can not be calculated according to the molar volume of the gas, so C is wrong; D. The amount of 15 g of ethane is 1 mol, and ethane contains 7 covalent bonds, so 1 mol of ethane contains $7 \mathrm {~N} _ { \mathrm { A } }$ covalent bonds, so D is wrong; The correct answer is B.

Question 22: 22. If $2.16 \mathrm { gX } _ { 2 } \mathrm { O } _ { 5 }$ contains 0.1 mol of oxygen atoms, then th...

22. If $2.16 \mathrm { gX } _ { 2 } \mathrm { O } _ { 5 }$ contains 0.1 mol of oxygen atoms, then the relative atomic mass of X is

  • A. A. 28
  • B. B. $28 \mathrm {~g} / \mathrm { mol }$
  • C. C. 14
  • D. D. $14 \mathrm {~g} / \mathrm { mol }$

Answer: C

Solution: According to the chemical formula of $\mathrm { X } _ { 2 } \mathrm { O } _ { 5 }$, $1 \mathrm { molX } _ { 2 } \mathrm { O } _ { 5 }$ has 5 mol of oxygen atoms, then the amount of $2.16 \mathrm { gX } _ { 2 } \mathrm { O } _ { 5 }$ is $\frac { 0.1 \mathrm {~mol} } { 5 } = 0.02 \mathrm {~mol}$, and according to the formula $n = \frac { m } { M }$, $M \left( \mathrm { X } _ { 2 } \mathrm { O } _ { 5 } \right) = \frac { 2.16 \mathrm {~g} } { 0.02 \mathrm {~mol} } = 108 \mathrm {~g} / \mathrm { mol }$, and according to any particle whose molar mass is given as $\mathrm { g } / \mathrm { mol }$, $M \left( \mathrm { X } _ { 2 } \mathrm { O } _ { 5 } \right) = \frac { 2.16 \mathrm {~g} } { 0.02 \mathrm {~mol} } = 108 \mathrm {~g} / \mathrm { mol }$ is $\mathrm { g } / \mathrm { mol }$. 4]] is $M \left( \mathrm { X } _ { 2 } \mathrm { O } _ { 5 } \right) = \frac { 2.16 \mathrm {~g} } { 0.02 \mathrm {~mol} } = 108 \mathrm {~g} / \mathrm { mol }$, and based on the fact that the molar mass of any particle in units of $\mathrm { g } / \mathrm { mol }$ is numerically equal to the relative atomic mass or relative molecular mass of that particle, it is known that $\mathrm { X } _ { 2 } \mathrm { O } _ { 5 }$ has a relative molecular mass of 108, and that X has a relative atomic mass $= \frac { 108 - 5 \times 16 } { 2 } = 14$; answer choice C. [Eye-point]The point of confusion in this question is that the relative atomic mass or relative molecular mass is numerically equivalent to the molar mass, the molar mass has a unit, its unit is $\mathrm { g } \cdot \mathrm { mol } ^ { - 1 }$, the relative molecular mass or relative atomic mass is unitless, it is easy to ignore the difference between the two and wrongly choose D when doing the question.

Question 23: 23. $\mathrm { N } _ { 2 } \mathrm { O }$ is a sweet-smelling, water-soluble, flammable colorless ga...

23. $\mathrm { N } _ { 2 } \mathrm { O }$ is a sweet-smelling, water-soluble, flammable colorless gas, which can stimulate the nerves to make people laugh, commonly known as "laughing gas"; it has an anesthetic effect, and has been used as a dental anesthetic, and the following values are not necessarily the same as the existing equivalent amount of laughing gas and carbon dioxide.

  • A. A. mass (in physics)
  • B. B. number of molecules
  • C. C. volumetric
  • D. D. atomic number

Answer: C

Solution: A. $m = n \times M$, there are equal amounts of two gases with equal molar masses, then the masses are equal, so $A$ is not chosen; B. According to $N = n \times N _ { A }$, if the amounts of substances are equal, then the numbers of molecules are equal, so B is not chosen; C. The volume of the gas is affected by the external conditions, there is no given state of the two gases, it is impossible to determine the size of the volume, so C choose; D. the two gases have equal number of molecules, and each molecule contains the same number of atoms, then the number of atoms is equal, so D is not selected; The answer is C.

Question 24: 24. Knowing Avogadro's constant, the molar mass and molar volume of a substance, the following physi...

24. Knowing Avogadro's constant, the molar mass and molar volume of a substance, the following physical quantities cannot all be approximated yet

  • A. A. Size and mass of molecules of a solid substance
  • B. B. Size and mass of molecules of liquid substances
  • C. C. Size and mass of molecules of gaseous substances
  • D. D. Mass of molecules of a gaseous substance

Answer: C

Solution: A. solid molecular gap is very small, negligible, so the size of the molecules of solid matter is equal to the ratio of the molar volume and Avogadro's constant, the mass of the molecules of solid matter is equal to the ratio of the molar mass and Avogadro's constant, so you can find the size of the molecules of the solid molecules and the mass of the molecules of solid, A is correct; B. liquid molecular gap is very small, negligible, so the size of the liquid substance molecules is equal to the ratio of the molar volume and Avogadro's constant, the mass of the liquid substance molecules is equal to the ratio of the molar mass and Avogadro's constant, so you can find out the size of the liquid molecules and the mass of the liquid molecules, B is correct; C. The gas molecules have a large gap, and the molar volume is equal to the product of the volume occupied by each molecule and Avogadro's constant, so the volume of the molecules cannot be estimated, C is incorrect; D. The mass of the molecules of a gaseous substance is equal to the ratio of the molar mass to Avogadro's constant, and the size of the space occupied by the molecules of a gaseous substance is equal to the ratio of the molar volume to Avogadro's constant, so the mass of the gas molecules can be estimated, and D is correct. Therefore, the answer is C. [Eyesight] by the molar volume and ${ } ^ { N _ { A } }$ calculate the size, by the molar mass and ${ } ^ { N _ { A } }$ calculate the quality of solid and liquid molecules gap is small, can be ignored; but the gas molecules of the size and mass are very small, the main factor in determining the volume of the gas molecules for the number of molecules.

Question 25: 25. The following statements are correct

25. The following statements are correct

  • A. A. The same volume of water and oxygen have the same number of molecules in standard conditions
  • B. B. If different gases have the same volume, they must contain the same number of molecules
  • C. C. At a certain temperature and pressure, the size of the volume of various gaseous substances is mainly determined by the number of molecules that make up the gas
  • D. D. The molar volume of a gas at standard conditions is the volume occupied by 1 mol of any substance which is approximately 22.4 L

Answer: C

Solution: A. Under standard conditions, water is not gaseous and oxygen is gaseous, and when the volume is the same, the amount of substance and the number of molecules are not the same, so A is wrong; B. Due to the number of molecules $N = n N _ { A } = \frac { V } { V _ { m } } N _ { A }$, as the state in which the gas is in is not clear, when the volume is the same, the amount of substance is not B. Since the number of molecules $N = n N _ { A } = \frac { V } { V _ { m } } N _ { A }$ is not clear, and the amount of substance is not the same when the volume is the same, the number of molecules contained is not necessarily the same; C. At a certain temperature and pressure, the value of the molar volume of the gas is determined, and the molecular spacing of the gaseous substance is larger than the molecular diameter, so the volume of the gas is not related to the size of the molecules, according to the volume of the gas $V = n V _ { m }$, it can be known that the volume of the gas and the amount of substance and the number of molecules are proportional to the volume of the gas, so C is correct; D. The molar volume of a gas applies only to gases, not to any substance, so D is wrong; The answer is C.

Question 26: 26. The size of the molar volume of a gas depends on

26. The size of the molar volume of a gas depends on

  • A. A. Amount of gas
  • B. B. Size of gas molecules
  • C. C. Distance between gas molecules
  • D. D. Relative molecular mass of the gas

Answer: C

Solution: The molar volume of a gas is the volume occupied by a unit amount of the gas, i.e., the volume occupied by 1 mol of the gas, for the For gases, the distance between molecules is much larger than the diameter of the molecules, the size of the molecules is negligible, so the size of the molar volume of the gas depends on the distance between the molecules. The answer is C.

Question 27: 28. The following statement about the molar volume of a gas is false

28. The following statement about the molar volume of a gas is false

  • A. A. The molar volume of a gas must be different for different temperatures and pressures.
  • B. B. The volume of a gas of the same quantity is determined mainly by temperature and pressure.
  • C. C. At $25 ^ { \circ } \mathrm { C }$ and 101 kPa, the molar volume of gas is approximately $24.5 \mathrm {~L} \cdot \mathrm {~mol} ^ { - 1 }$
  • D. D. The density of a gas at standard conditions is $1.25 \mathrm {~g} \cdot \mathrm {~L} ^ { - 1 }$ and the molar mass of the gas is $28 \mathrm {~g} \cdot \mathrm {~m} ^ { - 1 }$

Answer: A

Solution: A. The molar volume of gases is affected by temperature and pressure, at the same temperature and pressure, the molar volume of gases must be the same, at different temperatures and pressures, the molar volume of gases may be the same or different, so A is wrong; B. The volume of gas $\mathrm { V } = \mathrm { n } \mathrm { V } _ { \mathrm { m } }$, and the molar volume of gas is affected by temperature and pressure, so when the amount of gas n is the same, the size of the volume of gas depends on the temperature and pressure, so B is correct; C. According to PV $= \mathrm { nRT }$, under the same pressure, the ratio of the volume is equal to the ratio of the temperature, there are $\frac { V _ { m } } { 22.4 } = \frac { 298 } { 273 }$, the solution to the normal temperature and pressure, the molar volume of gas is $24.5 \mathrm {~L} / \mathrm { mol }$, so C is correct; D. The density of the gas $\rho = M / V _ { m }$, so the molar mass of the gas $M = \rho V _ { m }$, so the standard condition, the density of a gas is $125 \mathrm {~g} \cdot \mathrm {~L} ^ { - 1 }$, then the molar mass of the gas is $125 \mathrm {~g} \cdot \mathrm {~L} ^ { - 1 } \times 22.4 \mathrm {~L} \cdot \mathrm {~mol} ^ { - 1 } = 28 \mathrm {~g} \cdot \mathrm {~mol} ^ { - 1 }$, so D is correct. The answer is A.

Question 28: 29. A gas has a mass of 12.8 g and a volume of 4.48 L (standardized), the molar mass of the gas is

29. A gas has a mass of 12.8 g and a volume of 4.48 L (standardized), the molar mass of the gas is

  • A. A. 64
  • B. B. $64 \mathrm {~g} \cdot \mathrm {~mol} ^ { - 1 }$
  • C. C. 25.6
  • D. D. $25.6 \mathrm {~g} \cdot \mathrm {~mol} ^ { - 1 }$

Answer: B

Solution: Using $\mathrm { n } = \frac { \mathrm { m } } { \mathrm { M } } = \frac { \mathrm { V } } { \mathrm { Vm } }$, substitute the value $\frac { 12.8 \mathrm {~g} } { \mathrm { Mg } / \mathrm { mol } } = \frac { 4.48 \mathrm {~L} } { 22.4 \mathrm {~L} / \mathrm { mol } }$ and solve for $\mathrm { M } = 64 \mathrm {~g} \cdot \mathrm {~mol} ^ { - 1 }$. is correct; The answer is B. [Points] The students are prone to error is option A, students calculated the value of 64, that A is correct, the students ignored the molar mass is a unit, that is, when examining the molar mass, not only pay attention to the value, but also pay attention to the unit written on. $30 . \mathrm { B }$ [KNOWLEDGE POINT] $22.4 \mathrm {~L} / \mathrm { mol }$ Applicable conditions, Avogadro's law, molar volume of gases, microscopic factors that determine the size of a substance's volume [Detailed Explanation]A. The state (temperature and pressure of the gas) is unknown and Vm is uncertain, then the volume of 1 mol of any gas cannot be determined, so A is wrong; B. In the standard condition $\mathrm { Vm } = 22.4 \mathrm {~L} / \mathrm { mol }$, the volume of the gas is 22.4 L, then the amount of material of the gas 1 mol, the number of molecules contained in about $6.02 \times 10 ^ { 23 }$, so B is correct; C. The volume of a gas is affected by temperature and pressure, so it is not possible to determine whether the volume of a certain amount of any gas is greater than 22.4 L when the temperature is higher than $0 ^ { \circ } \mathrm { C }$, so C is wrong; D. If the temperature of the gas is unknown, the volume of 1 mol of any gas cannot be determined when the pressure is greater than 101 kPa, so D is wrong. The answer is B.

Question 29: 30 . The following statements are correct

30 . The following statements are correct

  • A. A. 1 mol of any gas has a volume of 22.4 L
  • B. B. At standard conditions, the volume of a gas is 22.4 L. The amount of substance of the gas is 1 mol, and the number of molecules it contains is approximately $6.02 \times 10 ^ { 23 }$
  • C. C. At temperatures above $0 ^ { \circ } \mathrm { C }$, the volume of a given amount of any gas is greater than 22.4 L
  • D. D. When the pressure is greater than 101 kPa, the volume of 1 mol of any gas is less than 22.4 L

Answer: B

Solution:

Question 30: 31.1 mol CO and $1 \mathrm {~mol} \mathrm { CO } _ { 2 }$ at standard conditions contain the same (1...

31.1 mol CO and $1 \mathrm {~mol} \mathrm { CO } _ { 2 }$ at standard conditions contain the same (1) Number of molecules (2) Number of atoms (3) Number of oxygen atoms (4) Number of carbon atoms (5) Volume

  • A. A. (1) (2)
  • B. B. (2) (3) (4)
  • C. C. (1) (2) (3) (4) (5)
  • D. D. (1) (4) (5)

Answer: D

Solution: CO and $\mathrm { CO } _ { 2 }$ have the same amount of substance, according to $\mathrm { N } = \mathrm { n } \cdot \mathrm { N } _ { \mathrm { A } }$, they have the same number of molecules, different numbers of atoms, oxygen atoms, and the same number of carbon atoms, and according to ${ } ^ { V = n \cdot V _ { m } }$, the labeled [[INLINE_FORMULA_3 ]] is the same, so the two volumes are also the same, so (1) (4) (5) meets the meaning of the question, the answer choose D.

Question 31: 32. Under the same conditions, $2 \mathrm {~mL} { } ^ { \mathrm { X } ( \text { 气 } ) }$ is the same...

32. Under the same conditions, $2 \mathrm {~mL} { } ^ { \mathrm { X } ( \text { 气 } ) }$ is the same as $5 \mathrm {~mL} ^ { \mathrm { C } _ { 2 } ( \text { 气 } ) \text { 恰好完全反应,生成 } 4 \mathrm {~mL} } \xrightarrow { \mathrm { AC } _ { 2 } ( \text { 气 } ) }$ and 2 $\mathrm { mL } \mathrm { B } _ { 2 } \mathrm { C } ($ with $)$, then the molecular formula of X is ( )

  • A. A. AB
  • B. B. $\mathrm { B } _ { 2 } \mathrm { C }$
  • C. C. $\mathrm { A } _ { 2 } \mathrm {~B} _ { 2 }$
  • D. D. $\mathrm { BC } _ { 2 }$

Answer: C

Solution: Under the same conditions, the ratio of the volumes of the different gases participating in the reaction is equal to the ratio of the stoichiometric numbers in the chemical equation, so the ratio of the stoichiometric numbers of $\mathrm { X } , \mathrm { C } _ { 2 } , \mathrm { AC } _ { 2 } , \mathrm {~B} _ { 2 } \mathrm { C }$ is $= 2 \mathrm {~mL} : 5 \mathrm {~mL} : 4 \mathrm {~mL} : 2 \mathrm {~mL} = 2 : 5 : 4 : 2$, so the reaction equation is $2 X + 5 C _ { 2 } = 4 A C _ { 2 } + 2 B _ { 2 } C$, and then combining with the conservation of atoms, we can get the chemical formula of has the chemical formula $A _ { 2 } B _ { 2 }$, so the answer is C.

Question 32: 33. In two containers of the same volume, one contains the gas $\mathrm { NH } _ { 3 }$ and the othe...

33. In two containers of the same volume, one contains the gas $\mathrm { NH } _ { 3 }$ and the other contains a mixture of $\mathrm { H } _ { 2 }$ and $\mathrm { N } _ { 2 }$. At the same temperature and pressure, the gases in the two containers must be identical ( ).

  • A. A. atomic number
  • B. B. number of molecules
  • C. C. mass (in physics)
  • D. D. intensity

Answer: B

Solution: A. The number of atoms per molecule in the two containers is not equal, so the number of atoms in the two containers with the same number of molecules is not equal, so A is wrong; B. Under the same temperature and pressure, the molar volumes of gases are equal, and different gases of the same volume have the same amount of substance and the same number of molecules, so B is correct; C. The average molar masses of the gases in the two containers are not necessarily equal, according to $\mathrm { m } = \mathrm { nM }$, the masses are not necessarily equal, so C is wrong; D. According to $\rho = M / V _ { m }$, the average molar masses of the gases in the two containers are not necessarily equal, so their densities are not necessarily equal, so D is wrong; The answer is B.

Question 33: 34. At room temperature, to the two volume of the same constant volume closed container were passed ...

34. At room temperature, to the two volume of the same constant volume closed container were passed $\mathrm { O } _ { 3 }$ and $\mathrm { O } _ { 2 }$, at this time the pressure in the two containers is equal to the two containers, the gas in the two containers must be the same ()

  • A. A. mass (in physics)
  • B. B. intensity
  • C. C. molecular total
  • D. D. atomic number

Answer: C

Solution: Gases have the same molar volume at room temperature and under the same pressure. By a corollary of Avogadro's law, gases of the same volume have the same amount of substance. For simplicity, assume that the amounts of substances are all 1 mol . A. The masses of $\mathrm { O } _ { 3 }$ and $\mathrm { O } _ { 2 }$ are 32 g and 48 g, respectively, which are not equal; B. According to Avogadro's Law, the ratio of the densities of gases is equal to the ratio of their relative molecular masses, so the ratio of the densities of $\mathrm { O } _ { 3 }$ and $\mathrm { O } _ { 2 }$ is equal to $48 \mathrm {~g} : 32 \mathrm {~g} = 3 : 2 , \mathrm {~B}$; C. If the amounts of $\mathrm { O } _ { 3 }$ and $\mathrm { O } _ { 2 }$ are equal, then the total number of molecules is equal; D. The total number of atoms in $1 \mathrm { molO } _ { 3 }$ and $\mathrm { O } _ { 2 }$ is 3 mol and 2 mol respectively.

Question 34: 35. At standard conditions, the following gases have the lowest density ().

35. At standard conditions, the following gases have the lowest density ().

  • A. A. $\mathrm { O } _ { 2 }$
  • B. B. $\mathrm { CH } _ { 4 }$
  • C. C. $\mathrm { H } _ { 2 } \mathrm {~S}$
  • D. D. $\mathrm { SO } _ { 2 }$

Answer: B

Solution:

Question 35: 36. At the same temperature and pressure, 50 mL of the gases $\mathrm { A } _ { 2 }$ and $100 \mathr...

36. At the same temperature and pressure, 50 mL of the gases $\mathrm { A } _ { 2 }$ and $100 \mathrm { mLB } _ { 2 }$ combine to form 50 mL of the gas C. The chemical formula of C is ( )

  • A. A. AB
  • B. B. $\mathrm { AB } _ { 2 }$
  • C. C. $\mathrm { A } _ { 2 } \mathrm {~B}$
  • D. D. $\mathrm { A } _ { 2 } \mathrm {~B} _ { 4 }$

Answer: D

Solution: Under the same temperature and pressure, 50 mL of gases $\mathrm { A } _ { 2 }$ and $100 \mathrm { mLB } _ { 2 }$ combine to form 50 mL of gas C, then according to Avogadro's law we can know that the ratio of the amounts of the three substances is $1 : 2 : 1$, which is $\mathrm { A } _ { 2 } + 2 \mathrm {~B} _ { 2 } = \mathrm { C }$. ], so according to the law of conservation of mass the chemical formula of C is $\mathrm { A } _ { 2 } \mathrm {~B} _ { 4 }$; Answer choice D.

Question 36: 37. As shown in the figure, two connected containers are separated by a piston, and the left and rig...

37. As shown in the figure, two connected containers are separated by a piston, and the left and right chambers (of the same volume) are each filled with a certain amount of NO and $\mathrm { O } _ { 2 }$, and it is exactly the same density of gas in the two containers. Open the piston, so that NO and $\mathrm { O } _ { 2 }$ fully reacted. The following judgment is correct (not considering the conversion of $\mathrm { NO } _ { 2 }$ to $\mathrm { N } _ { 2 } \mathrm { O } _ { 4 }$ ) ( ) ![](/images/questions/ideal-gas-law/image-003.jpg)

  • A. A. The left and right chambers have the same number of molecules at the beginning
  • B. B. The pressure in the NO chamber is the same before and after the reaction
  • C. C. The density in the final container is the same as the original
  • D. D. No $\mathrm { O } _ { 2 }$ present in the final container

Answer: C

Solution: A. If the volume of both containers is the same and the density is the same, then the mass of the gas is the same, because the molar mass of the two is different, so the amount of substance of the gas is different, and the number of molecules is different, A is wrong; B.Because the number of molecules of the gas on both sides is different, so the pressure is different, B error; C. According to the analysis of conservation of mass, the total mass of the gas is the same, the total volume of the container is the same, so the density is the same as the original, C is correct; D. The two have the same mass, because the molar mass of nitric oxide and oxygen is $30 : 32 = 15 : 16$, so the ratio of nitric oxide to oxygen is 16:15, and the two are reacted according to the ratio of 2:1, so there is surplus of oxygen, and D is wrong. The answer is C.

Question 37: 38. Avogadro performed the following experiment: "An evacuated closed vessel weighing Mg is filled w...

38. Avogadro performed the following experiment: "An evacuated closed vessel weighing Mg is filled with a mixture of NO and $\mathrm { H } _ { 2 }$ in the same quantity at standard conditions and weighed as $( \mathrm { M } + \mathrm { Q } ) \mathrm { g }$. The gas mixture is drained and then filled with $\mathrm { SO } _ { 2 }$ gas, and $\_\_\_\_$ g weights should be placed on the $\_\_\_\_$ side tray of the tray balance in order to balance the balance. "The lines should be filled in respectively ( )

  • A. A. Right ( $\mathrm { M } + 2 \mathrm { Q }$ )
  • B. B. Right ( $\mathrm { M } + 4 \mathrm { Q }$ )
  • C. C. Left $\quad ( \mathrm { M } + 2 \mathrm { Q } )$
  • D. D. Left $\quad ( \mathrm { M } + 4 \mathrm { Q } )$

Answer: B

Solution: When different gases are held in the same container under the same conditions, the number of molecules they contain must be equal. When NO and $\mathrm { H } _ { 2 }$ are mixed in the same amount, the average relative molecular mass of the gases is $\frac { 30 + 2 } { 2 } = 16$, and the relative molecular mass of $\mathrm { SO } _ { 2 }$ is 64. When weighing the mass of an object, the weights should be placed on the right pan of the balance. If the amount of gas in the closed container is $n$, the mass of the gas will be $\mathrm { H } _ { 2 }$ when filled with a mixture of NO and $\mathrm { H } _ { 2 }$ mixed in the same amount of gas and $16 n = \mathrm { Q } , n = \frac { \mathrm { Q } } { 16 }$ when filled with $16 n = \mathrm { Q } , n = \frac { \mathrm { Q } } { 16 }$. INLINE_FORMULA_6]] gas, the mass of the gas is $m = 64 n = 64 \times \frac { \mathrm { Q } } { 16 } = 4 \mathrm { Q }$ and the total mass of the container is $M + 4 \mathrm { Q }$. Answer choice B. [点睛]同一容器在同一条件盛放不同的气体时,所含分子数必然平等,所含物质的物质量也平等,求质量时,利用公式 $m = n M$进行计算.

Question 38: 39. Comparing two gases of equal mass $\mathrm { CO } _ { 2 }$ and $\mathrm { SO } _ { 2 }$ at the s...

39. Comparing two gases of equal mass $\mathrm { CO } _ { 2 }$ and $\mathrm { SO } _ { 2 }$ at the same temperature and pressure, the following statements are correct ( )

  • A. A. The density ratio is $13 : 16$
  • B. B. The density ratio is $16 : 11$
  • C. C. The volume ratio is $1 : 1$
  • D. D. The volume ratio is $16 : 11$

Answer: D

Solution: The molar masses of sulfur dioxide and carbon dioxide are $64 \mathrm {~g} / \mathrm { mol } , 44 \mathrm {~g} / \mathrm { mol }$ respectively; A. At the same temperature and pressure, the ratio of the densities of gases is equal to the ratio of the molar masses, so the ratio of the densities of carbon dioxide and sulfur dioxide gases is $44 \mathrm {~g} / \mathrm { mol } : 64 \mathrm {~g} / \mathrm { mol } = 11 : 16$, so A is wrong; B, at the same temperature and pressure, the ratio of the density of gases is equal to the ratio of molar masses, so the ratio of the densities of carbon dioxide and sulfur dioxide gas is: $44 \mathrm {~g} / \mathrm { mol } : 64 \mathrm {~g} / \mathrm { mol } = 11 : 16$, so B is wrong; C, at the same temperature and pressure, the ratio of the volume of gases of equal mass is inversely proportional to the molar mass, so the ratio of the volume of carbon dioxide and sulfur dioxide gas is: $64 \mathrm {~g} / \mathrm { mol } : 44 \mathrm {~g} / \mathrm { mol } = 16 : 11$, so C is wrong; D. At the same temperature and pressure, the ratio of the volume of equal masses of gases is inversely proportional to the molar mass, so the ratio of the volumes of carbon dioxide and sulfur dioxide gas is: $64 \mathrm {~g} / \mathrm { mol } : 44 \mathrm {~g} / \mathrm { mol } = 16 : 11$, so D is correct; Therefore, the answer is D. [点睛]根据气态方程: $\mathrm { pV } = = \mathrm { nRT }$ 可知,当 $\mathrm { p } , \mathrm {~T}$ 一定时,V与n成 比例;当 $\mathrm { V } , \mathrm {~T}$ 一定时,p与n成 比例;当当当 $\mathrm { p } , \mathrm {~V} , \mathrm {~T}$ 都一定时,气体的物质量,即Avogardia When $\mathrm { p } , \mathrm {~V} , \mathrm {~T}$ are both certain, the gas has the same amount of matter, Avogadro's law; according to the gas equation: $p V = = n R T$, it can be seen that $p \times M = = m / V R T = p \times M = \rho R T$ is directly proportional to $\rho$ when $p , T$ is certain, and $M$ is directly proportional to $\rho$. _13]] is proportional. $40 . \mathrm { B }$ [Knowledge Points]Derivation of gaseous substances with respect to NA, conditions for application of $22.4 \mathrm {~L} / \mathrm { mol }$, and calculations according to $n = N / N A$[Detailed Explanation] Let the molar mass of $A _ { 2 }$ be $M$ and the molar mass of $M$ be $M$. INLINE_FORMULA_19]] of $A _ { 2 }$ gas contains $n$ molecules, then there are $\frac { a } { M } = \frac { n } { N _ { A } }$, yielding $M = \frac { a N _ { A } } { n }$; let $m g$ be the molar mass of $m g$. INLINE_FORMULA_24]] of $A _ { 2 }$ gas in standard condition is $V$, then we have $\frac { m } { M } = \frac { V } { V _ { m } } , M = \frac { a N _ { A } } { n }$ and substitute it to get $V = \frac { m n V _ { m } } { a N _ { A } }$.

Question 39: 40. The $\mathrm { A } _ { 2 }$ gas of ag is known to contain n molecules, then the volume of the $\...

40. The $\mathrm { A } _ { 2 }$ gas of ag is known to contain n molecules, then the volume of the $\mathrm { A } _ { 2 }$ gas of mg at standard conditions is (let $\mathrm { N } _ { \mathrm { A } }$ be Avogadro's constant) ( ) Applications of the Ideal Gas Equation of State

  • A. A. 22.4 L
  • B. B. $22.4 \mathrm {~nm} / \mathrm { aN } _ { \mathrm { A } } \mathrm { L }$
  • C. C. $22.4 \mathrm { an } / \mathrm { mN } _ { \mathrm { A } } \mathrm { L }$
  • D. D. $22.4 \mathrm { am } / \mathrm { nN } _ { \mathrm { A } } \mathrm { L }$

Answer: B

Solution:
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Ideal Gas Law

理想气体状态方程

39 Practice Questions

Practice with Chinese questions to prepare for the CSCA exam. You can toggle translations while practicing.

Topic Overview

The ideal gas equation of state pV = nRT is the core formula that describes the quantitative relationship between pressure, volume, temperature and amount of matter of an ideal gas. In the examination, it is often combined with the analysis of experimental devices, chemical reaction calculations and comparison of gas properties, and requires flexible use of the equation to solve practical problems.

Questions:39

Key Points

  • 1Meanings and unit conversions of physical quantities in equations
  • 2Calculate the amount or volume of a gas in conjunction with a chemical reaction
  • 3Analyze the effect of temperature and pressure changes on the state of a gas
  • 4Using equations to derive gas density or molar mass

Study Tips

Proficiency in the difference between standard conditions and normal temperature and pressure conditions, noting the uniform conversion of temperature units (K or °C) and pressure units in the questions.

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