1) a) ΔH for the reaction between zinc and copper(II) sulfate solution is −219 kJ mol−1.
Construct a balanced equation for this reaction. (1 mark)
b) When the two are mixed together would you expect the temperature to rise or fall? Why? (2 marks)
c) 50 cm3 of a 1.0 mol dm−3 solution of copper(II) sulfate is reacted with an excess of zinc powder.
i) Calculate n, the moles of copper(II) sulfate. (1 mark)
ii)Now calculate q, the expected energy change in this reaction. (1 mark)
iii)Rearrange q = mcΔT to give ΔT. (1 mark)
iv) Given that c = 4.18 J K−1 g−1 calculate the maximum expected temperature rise for this reaction. (1 mark)
d) Calculate the maximum expected temperature rise if the experiment is repeated with:
i) 50 cm3 of 0.5 mol dm−3 copper sulfate solution (2 marks)
ii) 100 cm3 of 0.5 mol dm−3 copper sulfate solution. (2 marks)