CAIE A Level Chemistry 9701 · Group 2
Barium oxide and barium carbonate are both Group 2 compounds. Describe and compare their separate reactions with water and with dilute hydrochloric acid. For each reaction, state what you would observe and write a balanced equation.
5 marks, so the mark scheme is looking for about 5 separate creditworthy points. Making the same point twice in different words earns it once.
Compare means: Give similarities or differences between two things, and say which side each point belongs to. Write each point as a pair, for example: A is X, whereas B is Y. Two separate descriptions rarely earn the marks.
Written by Markquill to follow the Cambridge International syllabus. Markquill is independent and is not affiliated with or endorsed by Cambridge International.