Question

which is the molecular formula of an alkyne? c₁₀h₁₈ c₉h₁₈ c₈h₁₈ c₁₀h₂₀ c₉h₂₀

Explanation:

Step1: Recall alkyne formula

Alkynes have general formula \( C_nH_{2n - 2} \) (where \( n\geq2 \)).

Step2: Check each option

• For \( C_{10}H_{18} \): Let \( n = 10 \). Then \( 2n-2=2\times10 - 2=18 \). Matches the formula.
• For \( C_9H_{18} \): \( 2n - 2=2\times9-2 = 16

eq18 \).

• For \( C_8H_{18} \): \( 2n - 2=2\times8 - 2=14

eq18 \).

• For \( C_{10}H_{20} \): \( 2n - 2=2\times10-2 = 18

eq20 \).

• For \( C_9H_{20} \): \( 2n - 2=2\times9-2 = 16

eq20 \).

Answer:

\( \boldsymbol{C_{10}H_{18}} \)