1. Measuring moles of GASES by measuring their volumes

2. Experiments show that at room temperature and pressure one mole of ANY gas occupies 24dm 3 (24000cm 3 ) Hence, if the volume of a gaseous sample is measured, at room temperature and pressure, the number of moles (n) of gas in the sample can be calculated using n = V dm3 / 24

3. What is the volume (cm 3 ) of 3g of ethane gas at rtp? Molecular Formula of ethane = C 2 H 6 Moles = mass = 3/30 = 0.1 moles Molar mass Vol = 24000 x No of moles. Answer = 2400cm 3 6g of a hydrocarbon gas had a volume of 4.8 dm 3. Calculate its Molar Mass. Moles = Volume/24dm 3 = 4.8/24 = 0.2 Molar mass = Mass/moles =6/0.2 Answer 30

4. Q1Calculate the number of moles present, if a gas sample has a volume of 20.0 dm 3 at room temperature and pressure. n = V dm3 / 24 = 0.833 moles = 20 / 24

5. n = V dm3 / 24 = 0.00417 moles = 0.100 / 24 Q2 a sample of gas weighs 0.272g. It has a volume of 100cm 3 at a room temperature pressure. Calculate the number of moles of gas in the sample and hence the mass of one mole of the gas. Mass of one mole = 0.272 0.00417 = 65.2 g