Question

Consider a container with 6.90g of N₂ gas and an unknown mass of CO₂ gas. If we know that the partial pressure of the CO₂ is twice that of the N₂, determine the mass of CO₂ gas in the container.

Mass of CO₂ gas in the container (enter to two decimal places) = _______ g

Answer 1

Ans :

Mol N2 = mass / molar mass

= 6.90 g / 28.0134 g/mol

= 0.246 mol

Partial pressure of gas is directly proportional to its mole fraction which is directly proportional to the number of moles of gas in the mixture

So if the N2 gas is 0.246 mol , so for CO2 gas , the number of mol of CO2 gas will be :

= 2 x 0.246 mol

= 0.4926 mol

Mass of CO2 = mol x molar mass

= 0.4926 mol x 44.01 g/mol

= 21.68 grams