What is the molar mass of the gas? I was going to do D=GFM(P)/(RT) but I don't have the density.. Created by Brittany. science-mathematics-en - chemistry-en

A 0.860 g sample of an unknown gas exerts a pressure of 735 mm Hg in a 463 mL container at 22°C.?

May 2021 2 17 Report

A 0.860 g sample of an unknown gas exerts a pressure of 735 mm Hg in a 463 mL container at 22°C.?

What is the molar mass of the gas? I was going to do D=GFM(P)/(RT) but I don't have the density.

Use the gas law equation to calculate the moles present

PV = nRT

P = pressure = 735/760 = 0.967 atm

V = 463mL = 0.463L

n = ??

R = 0.082057

T = 273+22 = 295K

Substitute:

0.967 * 0.463 = n* 0.082057*295

n = 0.0185 mol

0.860g = 0.0185mol

1 mol = 0.860/0.0185 = 46.5g/mol

Molar mass of gas = 46.5g/mol.

You do not require the density of the gas for this type of problem.