Identify the atoms that are oxidized and reduced, the change in oxidation state for each, and the oxidizing and reducing agents in each of the following equations: (a) mg(s) + nicl2 (aq) ⟶ mgcl2 (aq) + ni(s) (b) pcl3 (l) + cl2 (g) ⟶ pcl5 (s) (c) c2 h4 (g) + 3o2 (g) ⟶ 2co2 (g) + 2h2 o(g) (d) zn(s) + h2so4 (aq) ⟶ znso4 (aq) + h2 (g) (e) 2k2s2 o3 (s) + i2 (s) ⟶ k2s4 o6 (s) + 2ki(s) (f) 3cu(s) + 8hno3 (aq) ⟶ 3cu(no3 )2 (aq) + 2no(g) + 4h2 o(l)