Classifying and Naming Organic Compounds

How the real exam tests it

Questions from real CSCA papers that test this concept. Work each one out before you open the answer.

1. CSCA Chemistry April 2026 Past Paper
   The name of $\mathrm{CH_{2}{=}CHCH_{3}}$ is ( ).
   • A. Propane
   • B. Propene
   • C. Propyne
   • D. Propanol
   Show answer & solution

   Answer: B

   Answer: B $\mathrm{CH_{2}{=}CHCH_{3}}$ contains a carbon-carbon double bond; it is propene.
   Take the full CSCA Chemistry April 2026 Past Paper — timed & graded
2. CSCA Chemistry March 2026 Past Paper
   Which organic compound is named incorrectly？
   • A．$\mathrm { CH } _ { 3 } \mathrm { CH } _ { 2 } \mathrm { CH } _ { 2 } \mathrm { CH } _ { 3 }$－butane
   • B．$\mathrm { CH } _ { 3 } \mathrm { C } \equiv \mathrm { CCH } _ { 3 } - 2$-butyne
   • C．$\mathrm { CH } _ { 3 } \mathrm { CH } \left( \mathrm { CH } _ { 3 } \right) \mathrm { CH } _ { 2 } \mathrm { OH }$ - 2-methyl-1-propanol
   • D．$\mathrm { CH } _ { 3 } \mathrm { COCH } _ { 3 }$ - propionaldehyde
   Show answer & solution

   Answer: D

   $\mathrm { CH } _ { 3 } \mathrm { COCH } _ { 3 }$ is acetone (ketone). Propionaldehyde $= \mathrm { CH } _ { 3 } \mathrm { CH } _ { 2 } \mathrm { CHO }$. Answer: D．
   Take the full CSCA Chemistry March 2026 Past Paper — timed & graded