Question

A sample of unknown gas is placed in a 2.5 L bulb at a pressure of 360 torr and at a temperature of 22.5°C and is found to weight 1.6616 g. The molecular weight of the gas is closest to

(a) 80 g

(b) 55 g

(c) 34 g

(d) 55 g

Answer 1

Answer is : (c) 34 g

According to ideal gas equation,

pV = nRT

Given,

Pressure = 360 torr = 360/760 atm

Volume = 2.5

Temperature = 22.5+273 = 295.5 K

Weight of a gas = 1.6616

Substituting the values,

≈ 34 g