Question

A mixture of CO AND CO2 is found to have a density of 1.5gL at 303K and 730 torr.what is the composition of the mixture

Answer 1

Molar mass of CO = (12.01 + 16.00) g/mol = 28.01 g/mol,

Molar mass of CO₂ = (12.01 + 16.00×2) g/mol = 44.01 g/mol, the mixture contains y% of CO and (1 - y%) of CO₂.

Average molar mass = [28.01 × y% + 44.01 × (1 - y %)] g/mol = (44.01 - 0.16y) g/mol. For the gaseous mixture : Pressure,

P = 740 mmHg,

Density, d = 1.50 g/L ,

Molar mass, M = (44.01 - 0.16y) g/mol,

Gas constant, R = 62.36 mmHg L / (mol K) , Temperature, T = (273 + 20) K = 293 K,

PV = nRT, PV = (m/M)RT , PM = (m/V)RT , PM = dRT, M = dRT/P, 44.01 - 0.16y = 1.50 × 62.36 × 293 / 740, 44.01 - 0.16y = 37.04 , 0.16y = 6.97, y = 43.6, 100 - y = 56.4. The mixture contains 43.6% of CO and 56.4% of CO₂.

Answer 2

43.6 % = CO

56.4 % = CO2