Question

Use the molar volume of a gas at STP to calculate the density (in ) of carbon dioxide gas at STP.

Answer 1

The volume of any gas at standard temperature and pressure is 22.4L. Density is simply equal to mass over volume, so the only thing we don't have yet is the mass, or do we?

According to the periodic table the atomic masses of carbon and oxygen can be found to be C =12.01 and O=16.0. Since carbon dioxide is CO2 that means we need to add up 1 carbon and 2 oxygen for a total of 44.0g are in one mole of CO2

44.0g/22.4L = 1.96 g/L is the density of CO2. If you want it in mL just multiply it by 100ml/1L to get 196g/mL.