On heating, metal carbonates break down and release a gas that makes limewater go milky.
A student studies how quickly four metal carbonates decompose using the apparatus shown.
The student:
- heats each metal carbonate separately with a Bunsen burner
- records the time taken for the limewater to become milky.
The results are displayed in the table.
(a)[1]
State the gas that causes limewater to turn milky.
(b(i))[2]
Suggest two ways in which the heat supplied by the Bunsen burner is kept constant.
(b(ii))[2]
Suggest two other variables that must be controlled.
(c)[1]
Which metal carbonate breaks down most slowly?
(d)[2]
Suggest how the investigation could be improved so that the results are more reliable.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “CO2” …