CAIE A Level Chemistry 9701 · Group 2
A student heats a sample of barium nitrate strongly and observes that a brown gas is evolved and a white solid remains.
(a) Write the equation for the thermal decomposition of barium nitrate.
(b) Suggest how the thermal stability of barium nitrate compares with that of magnesium nitrate, and explain your answer in terms of the ions involved.
6 marks, so the mark scheme is looking for about 6 separate creditworthy points. Making the same point twice in different words earns it once.
Suggest means: Apply what you know to an unfamiliar situation. There may be more than one acceptable answer. Reason from the principle you have learned to the new context, and say which principle you are using.
Written by Markquill to follow the Cambridge International syllabus. Markquill is independent and is not affiliated with or endorsed by Cambridge International.