At 300 K, a sample of 3.0 g of gas A occupies the same volume as 0.2 g of hydrogen at 200 K at the same pressure. The molar mass of gas A is _____ g $\mathrm{mol}^{-1}$ (nearest integer) Assume that the behaviour of gases as ideal. (Given: The molar mass of hydrogen $\left(\mathrm{H}_{2}\right)$ gas is $2.0 \mathrm{~g} \mathrm{~mol}^{-1}$)

JEE Main · 2022 · 24 Jun 2022 · Shift 2 · Some Basic Concepts of Chemistry

At 300 K, a sample of 3.0 g of gas A occupies the same volume as 0.2 g of hydrogen at 200 K at the same pressure. The molar mass of gas A is _____ g

mol^{- 1}

(nearest integer) Assume that the behaviour of gases as ideal. (Given: The molar mass of hydrogen

(H_{2})

gas is

2.0 g mol^{- 1}

)

Answer: 45

For ideal gases at the same pressure and volume,

n_{1} T_{1} = n_{2} T_{2}

. For gas A:

\frac{3}{M _{A}} \times 300 = \frac{0.2}{2} \times 200

. Solving:

\frac{900}{M _{A}} = 20

, so

M_{A} = 45

g/mol.

JEE Main · 2022 · 24 Jun 2022 · Shift 2 · Integer answer