Collection of gases-IGCSE /GCSE CHEMISTRY

Collection and identification of gases

Methods for collecting gasesdownward deliverysuitable for heavy dense gas solubility not important e.g. chlorine, upward deliverysuitable for light low density gas, solubility not important e.g hydrogen

collection over waterSuitable for any gas with a low solubility e.g. nitrogencollection using a gas syringeSuitable for any gas especially if volume is to be measured.Learning activity - use the data in the table and the rules above to select a collection method and give a reason.

Hazards with common gasesHydrogen - flammable, explosive when mixed with air. Use in small amounts.Hydrogen chloride and sulphur dioxide- poisonous as they are very acidic. Use small amounts and only in the fume cupboard.