Question

What is the number of structural isomers possible for alkene with molecular formula \(\text{C}_5\text{H}_{10}\) ?

• A. 2
• B. 3
• C. 4
• D. 5

Hint:

For \(\text{C}_5\text{H}_{10}\), count only constitutional isomers unless the question specifically asks for geometrical isomers too.

Answer 1

The Correct Option is D

Concept:
Structural isomers differ in connectivity of atoms. For alkenes with formula \(\text{C}_5\text{H}_{10}\), we count only different structural arrangements, not geometrical isomers. ip

Step 1: Write possible open-chain alkene isomers.
The structural isomers are:
• pent-1-ene
• pent-2-ene
• 2-methylbut-1-ene
• 3-methylbut-1-ene
• 2-methylbut-2-ene e} ip

Step 2: Count them.
Total number of structural isomers: \[ 5 \] ip Hence, the correct answer is:
\[ \boxed{(D)\ 5} \]