CAIE A Level Chemistry 9701 · Group 2
Describe and explain the trend in the thermal stability of the carbonates and nitrates of the Group 2 elements from magnesium to barium. Also describe and explain the variation in solubility of the hydroxides and sulfates of these elements in terms of the relative magnitudes of the enthalpy change of hydration and the lattice energy.
7 marks, so the mark scheme is looking for about 7 separate creditworthy points. Making the same point twice in different words earns it once.
Describe means: Say what happens or what something is like, in order and with detail. You are not being asked why. If there is data, quote it: name the trend, then give figures with units at the points where it changes.
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