Choose from the gases to answer the questions. ammonia carbon dioxide chlorine butane hydrogen nitrogen oxygen propane sulfur dioxide Each gas can be used once, more than once or not at all. Which gas:

1. (a)burns in air to give only water[1]
2. (b)is used to kill bacteria in the purification of water for domestic use[1]
3. (c)has a molecule containing only 11 atoms[1]
4. (d)occupies 78% by volume of dry air[1]
5. (e)is released when calcium hydroxide is added to soil that contains the fertiliser ammonium nitrate?[1]