An architectural conservator is investigating a historical mortar sample, which consists mainly of calcium carbonate.
How could the conservator test a fragment of the mortar sample to show the presence of carbonate ions?
Complete the sentences by choosing the correct substance from the box below.
[ acidified barium chloride, limewater, nitric acid, silver nitrate, sodium hydroxide ]
When heated strongly, calcium carbonate undergoes thermal decomposition:
calcium carbonate→calcium oxide+carbon dioxide\text{calcium carbonate} \rightarrow \text{calcium oxide} + \text{carbon dioxide}calcium carbonate→calcium oxide+carbon dioxide
To heat the sample, the conservator uses a spirit burner that burns liquid ethanol (C2H5OH\text{C}_2\text{H}_5\text{OH}C2H5OH).
Give two ways in which carbon dioxide, a greenhouse gas, is released into the atmosphere during this procedure.