Which of the following reactions are redox reactions? For those reactions that are redox reactions, identify the substance being oxidized and the substance being reduced.
a. Zn(s) + CoCl2(aq) ------> ZnCl2(aq) + Co(s)
b. HI(aq) + NaOH(aq) -------> H2O(I) + NaI(aq)
c. AgNO3(aq) + NaCI(aq) --------> AgCI(s) + NaNO3(aq)
d. 2 K(s) +Br2(I) --------> 2 KBr(s) 
Additional Requirements 
Level of Detail: Only answer needed