Determine whether each reaction is a redox reaction. For each redox reaction, identify the oxidizing agent and the reducing agent. a. Al(s) + 3 Ag+ (aq)¡Al3 + (aq) + 3 Ag(s) b. SO3( g) + H2O(l )¡H2SO4(aq) c. Ba(s) + Cl2( g)¡BaCl2(s) d. Mg(s) + Br2(l )¡MgBr2(s)