4. (a). When a solution of barium nitrate and sodium sulphate are mixed, white insoluble barium sulphate forms. (1). Write balanced molecular, total ionic, and net ionic equations for the above reaction. (ii). Identify the precipitate and spectator ions for the reaction. (9 marks) 3 (b). (1). Classify each of the following redox reactions (Reaction I - III) as a combination, decomposition, or displacement reaction. Reaction 1: Se(s) + F2(g) SF4(9) Reaction II: 2H2O2(1) 2H2O(l) + O2(g) Reaction III: Ni(NO3)2(aq) + Cr(s) - Ni(s) + Cr(NO3)3(aq) (1) Write a balanced molecular equation for each reaction in ()., as well as total and net ionic equations for Reaction III. (i). Identify the oxidising and reducing agents for each reaction in (i). (14 marks)