A-LevelChemistryChemical energeticsMay/June 2018Paper 3 Q215 Marks
2 In this experiment you will determine the enthalpy change, ∆H, for the decomposition of calcium hydroxide to calcium oxide. Ca(OH)2(s) → CaO(s) + H₂O(I) To do this, you will determine the enthalpy changes for the reactions of calcium hydroxide and calcium oxide with hydrochloric acid. Excess acid will be used for both experiments. You will then use Hess' Law to calculate the enthalpy change for the reaction above. FB 2 is 3.0 mol dm⁻³ hydrochloric acid, HCl. FB 3 is calcium hydroxide, Ca(OH)2. FB 4 is calcium oxide, CaO.
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