The complete combustion of 0.492 g of an organic compound containing 'C', 'H' and 'O' gives 0.793 g of $\ce{CO2}$ and 0.442 g of $\ce{H2O}$. The percentage of oxygen composition in the organic compound is ______. (nearest integer)

JEE Main · 2022 · 28 Jun 2022 · Shift 2 · Some Basic Concepts of Chemistry

The complete combustion of 0.492 g of an organic compound containing 'C', 'H' and 'O' gives 0.793 g of

CO X_{2}

and 0.442 g of

H X_{2} O

. The percentage of oxygen composition in the organic compound is ______. (nearest integer)

Answer: 46

From combustion data:

Moles of C = moles of

CO X_{2}

\frac{0.793}{44}

Mass of C =

\frac{0.793}{44} \times 12 = 0.216

g

Moles of H =

2 \times

moles of

H X_{2} O

\frac{0.442}{18} \times 2

Mass of H =

\frac{0.442}{18} \times 2 \times 1 = 0.049

g

Mass of O = Total mass - (mass of C + mass of H)
=

0.492 - 0.216 - 0.049 = 0.227

g

Percentage of O =

\frac{0.227}{0.492} \times 100 = 46.13% \approx 46%

JEE Main · 2022 · 28 Jun 2022 · Shift 2 · Integer answer