Choose from the list of compounds to answer these questions. calcium oxide carbon dioxide carbon monoxide lead chloride propan-1-ol sodium nitrate sodium sulfate sulfur dioxide water Each compound may be used once, more than once or not at all. Identify the compound that:

1. (a)is a toxic gas produced by the incomplete combustion of carbon-containing compounds[1]
2. (b)turns anhydrous copper(II) sulfate blue[1]
3. (c)leads to deoxygenation of water in rivers[1]
4. (d)in aqueous solution, gives a white precipitate on addition of acidified aqueous barium chloride[1]
5. (e)contains an anion with a charge of -1.[1]