Question: What volume of gas is produced by vaporizing a given volume of dry ice?

Andrew McKinley answered on 20 Nov 2014:

A ‘volume’ of dry ice… We tend not to work in volumes of solids, we tend to think of masses of dry ice (which is simply frozen carbon dioxide, CO2)

There is a relationship which dictates the volume taken up by a given quantity of gas: it says that one mole of gas (that is about 600,000,000,000,000,000,000,000 molecules of gas – 6 followed by 23 zeros! This is Avogadro’s number and is mindbogglingly huge!) take up 24 litres of space at room temperature and pressure.

So, 44 g of carbon dioxide (CO2 has a relative molecular mass of 12+16+16 = 44g per mole) has this 6×10^(23) molecules of carbon dioxide, and will take up 24 litres of space.

Put it another way, about 20 pellets of solid CO2, each about 1cm long, will expand to fill 24 litres of space. It’s quite a big expansion!