CIE iGCSE Co-Ordinated Science C11.2 Naming organic compounds Exam Style Questions Paper 2
▶️ Answer/Explanation
The displayed formula shows an –OH (hydroxyl) group attached to a carbon chain, which is the functional group of alcohols. Polymers are long chains, alkanes have only single C–C bonds, and alkenes have a C=C double bond. Thus compound P is an alcohol.
✅ Answer: (B)
✅ Answer: (B)
▶️ Answer/Explanation
But-2-ene is an alkene with four carbon atoms and a double bond between carbon 2 and carbon 3. The structure must have a double bond in the middle, giving \(\mathrm{CH_3-CH=CH-CH_3}\). Option A shows but-1-ene (double bond at carbon 1). Option B shows butane (an alkane, no double bond). Option C shows but-1-ene (double bond at carbon 1). Option D correctly shows the double bond between carbons 2 and 3.
✅ Answer: (D)
✅ Answer: (D)
▶️ Answer/Explanation
But-1-ene has 4 carbon atoms with the C=C double bond starting at carbon 1.
This gives the structure \( CH_3CH_2CH{=}CH_2 \), with the double bond between the first and second carbons.
Option D is but-2-ene (double bond in the middle), and B is butane (no double bond).
✅ Answer: (C)
This gives the structure \( CH_3CH_2CH{=}CH_2 \), with the double bond between the first and second carbons.
Option D is but-2-ene (double bond in the middle), and B is butane (no double bond).
✅ Answer: (C)
Question
Which compound name matches the structure shown? 
▶Answer/Explanation
Ans :B
Question
Which formula represents but-1-ene?
(A) CH$_{3}$CH=CH$_{2}$
(B) CH$_{3}$CH$_{2}$CH$_{2}$CH$_{3}$
(C) CH$_{3}$CH$_{2}$CH=CH$_{2}$
(D) CH$_{3}$CH=CHCH$_{3}$
▶️Answer/Explanation
Ans : C