Question

When a hydrocarbon A undergoes complete combustion it requires 11 equivalents of oxygen and produces 4 equivalents of water. What is the molecular formula of $A$?

• A. $C _{11} H _8$
• B. $C _{11} H _4$
• C. $C _5 H _8$
• D. $C _9 H _8$

Answer 1

Answer: (D)

$C _9 H _8$

Answer 2

Cx​Hy​+(x+4y​)O2​→xCO2​+2y​H2​O
2y​=4∴y=8
x+48​=11
∴x=9
∴ Hydrocarbon will be=C9​H8​
So, the correct option is (D): $C_9H_8$