A gaseous hydrocarbon gives upon combustion 0.72 g of water and 3.08 g of CO2. The empirical formula of the hydrocarbon is

Question

A gaseous hydrocarbon gives upon combustion 0.72 g of water and 3.08 g of CO2. The empirical formula of the hydrocarbon is (A) C2H4 (B) C3H4 (C) C6H5 (D) C7H8

Tardigrade Admin · Accepted Answer

18 g H2O contains 2g H ∴ 0.72 g H2O contains 0.08 g H 44 g CO2, contains 12 g C ∴ 3.08 g CO2 contains 0.84 g C ∴ C: H = (0.84/12): (0.08/1) = 0.07: 0.08 = 7:8 ∴ Empirical formula = C7H8

Q. A gaseous hydrocarbon gives upon combustion $0.72 g$ of water and $3.08 g$ of $C O_{2}$ . The empirical formula of the hydrocarbon is

$C_{2} H_{4}$

$C_{3} H_{4}$

$C_{6} H_{5}$

$C_{7} H_{8}$

18 g $H_{2} O$ contains $2 g H$
$∴ 0.72 g H_{2} O$ contains $0.08 g H$
$44 g C O_{2}$ , contains $12 g C$
$∴ 3.08 g C O_{2}$ contains $0.84 g C$
$∴ C : H = \frac{0.84}{12} : \frac{0.08}{1}$
$= 0.07 : 0.08 = 7 : 8$
$∴$ Empirical formula $= C_{7} H_{8}$

Q. A gaseous hydrocarbon gives upon combustion 0.72g of water and 3.08g of CO2​. The empirical formula of the hydrocarbon is

C2​H4​

C3​H4​

C6​H5​

C7​H8​