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 \( n \geq 2 \)).

Step2: Test each option

• For \( C_{10}H_{18} \): Let \( n = 10 \). Then \( 2n - 2 = 2(10)-2 = 18 \). Matches.
• For \( C_9H_{18} \): \( 2(9)-2 = 16

eq 18 \).

• For \( C_8H_{18} \): \( 2(8)-2 = 14

eq 18 \).

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

eq 20 \).

• For \( C_9H_{20} \): \( 2(9)-2 = 16

eq 20 \).

Answer:

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