Question

A gas mixture is composed of 4.3 grams of hydrogen (density at STP = 0.089 g/L) and 2.9 grams of helium (density at STP = 0.179 g/L). What is the percentage (v/v) helium in the mixture?

If v/v = Volume of gas/total volume how would we find the volume of both of the gases?

Answer 1

Convert g H2 to volume using 1 mol H2 occupies 22.4 L at STP (alternatively you can use the PV = nRT and solve for volume). Convert g He to volume He the same way. Then plug into your v/v formula and solve for percent each.