Are the following changes exothermic or endothermic? Explain your answer.
i) 2Al(s) + Fe2O2(s) = Al2O3(s) + 2Fe(s)
ii) HCl(aq) + NaOH(aq) = NaCl(aq) + H2O(l)
iii) H2O(s) = H2O(l)