9. Which of the following equations represent redox reactions? For each redox reaction,
determine which atom is oxidized and which
is reduced, and identify the oxidizing agent
and the reducing agent.
a. MgO(s) + H2CO3(aq) →

MgCO3(s) + H2O(l)
b. 2KNO3(s) → 2KNO2(s) + O2(g)
c. H2(g) + CuO(s) → Cu(s) + H2O(l)
d. NaOH(aq) + HCl(aq) →NaCl(aq) + H2O(l)
e. H2(g) + Cl2(g) → 2HCl(g)
f. SO3(g) + H2O(l) → H2SO4(aq)