CIE Jun 2016 v2 Paper 4 Q8

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PMT (a) Describe and explain the trend in the solubility of the hydroxides down Group 2. 16[3] (b) Calcium reacts vigorously with HCl (aq) producing H2(g). Ca(s) + 2HCl (aq)CaCl 2(aq) + H2(g) (i) How would you expect the enthalpy change for this reaction to compare with the enthalpy change for the reaction where HNO3(aq) is used in place of HCl but all other conditions are the same? Explain your answer.[1]UCLES 2016 9701/42/M/J/16<br /> PMT (ii) The ionic equation for this reaction is shown. 17 Ca(s) + 2H+(aq)Ca2+(aq) + H2(g) H o = x kJ mol1 Construct a fully labelled Hess Law cycle to connect each side of this equation to the relevant gas phase ions. Use your cycle, the following data, and data from the Data Booklet, to calculate a value for x. standard enthalpy of atomisation of Ca(s), (Ca) +178 kJ mol1 standard enthalpy of hydration of Ca2+(g), (Ca2+) 1576 kJ mol1 standard enthalpy of hydration of H+(g), (H+) 1090 kJ mol1 x =kJ mol1 [4] (c) The standard enthalpy change for the reaction between Ca(s) and CH3CO2H(aq) is less negative than x by 2 kJ mol1. Suggest an explanation for this.[2]UCLES 2016 9701/42/M/J/16 [Total: 10] [Turn over<br />

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