25 g of an unknown hydrocarbon upon burning produces 88 g of $\mathrm{CO}_{2}$ and 9 g of $\mathrm{H}_{2} \mathrm{O}$. This unknown hydrocarbon contains.

(A) 24 g of carbon and 1 g of hydrogen

(B) 22 g of carbon and 3 g of hydrogen

(C) 18 g of carbon and 7 g of hydrogen

(D) 20 g of carbon and 5 g of hydrogen

JEE Main · 2019 · 12 Apr 2019 · Shift 2 · Some Basic Concepts of Chemistry

25 g of an unknown hydrocarbon upon burning produces 88 g of

CO_{2}

and 9 g of

H_{2} O

. This unknown hydrocarbon contains.

Answer: (A)

All the carbon ends up in

CO X_{2}

\frac{88}{44} = 2

mol of

CO X_{2}

carries

2 \times 12 = 24

g of carbon. All the hydrogen ends up in water:

\frac{9}{18} = 0.5

mol of

H X_{2} O

carries

0.5 \times 2 = 1

g of hydrogen. Together

24 + 1 = 25

g, matching the sample, so it contains

24

g of carbon and

1

g of hydrogen.

JEE Main · 2019 · 12 Apr 2019 · Shift 2 · Single correct option