The pressure exerted by a non- reactive gaseous mixture of 6.4 g of methane and 8.8 g of carbon dioxide in a 10 L vessel at \(27^{\circ} \mathrm{C}\) is \_\_\_\_ kPa . (Round off to the nearest integer). [ Assume gases are ideal, \(\mathrm{R}=8.314 \mathrm{~J} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}\) Atomic masses : C : \(12.0 \mathrm{u}, \mathrm{H}: 1.0 \mathrm{u}, \mathrm{O}: 16.0 \mathrm{u}\) ]

JEE Main · 2021 · 17 Mar 2021 · Shift 1 · Some Basic Concepts of Chemistry

The pressure exerted by a non- reactive gaseous mixture of 6.4 g of methane and 8.8 g of carbon dioxide in a 10 L vessel at

2 7^{\circ} C

is ____ kPa .
(Round off to the nearest integer).
[ Assume gases are ideal,

R = 8.314 J mol^{- 1} K^{- 1}

Atomic masses : C :

12.0 u, H : 1.0 u, O : 16.0 u

]

Answer: 150

Methane has molar mass

16

g mol

^{- 1}

and carbon dioxide

44

g mol

^{- 1}

, so the vessel holds

\frac{6.4}{16} = 0.4

mol of methane and

\frac{8.8}{44} = 0.2

mol of carbon dioxide. The gases do not react, so the total amount of gas is

n = 0.6

mol and the ideal gas equation applies to the mixture as a whole with

V = 10

= 1 0^{- 2}

^{3}

and

T = 300

P = \frac{n R T}{V} = \frac{0.6 \times 8.314 \times 300}{1 0 ^{- 2}} Pa

This gives

P = 1.4965 \times 1 0^{5}

= 149.65

kPa, which to the nearest integer is

150

kPa.

JEE Main · 2021 · 17 Mar 2021 · Shift 1 · Integer answer