Tell which of the following are oxidation–reduction reactions. For those that are, identify the oxidizing agent, the reducing agent, the substance being oxidized, and the substance being reduced.

a. CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(g)

b. Zn(s) + 2HCl(aq) → ZnCl₂(aq) + H₂(g) 

c. Cr₂O₇^2-(aq) + 2OH^-(aq) → 2CrO₄^2-(aq) + H₂O(l)

d. O₃(g) + NO(g) → O₂(g) + NO₂(g) 

e. 2H₂O₂(l) → 2H₂O(l) + O₂(g)

f. 2CuCl(aq) → CuCl₂(aq) + Cu(s)

g. HCl(g) + NH₃(g) → NH₄Cl(s)

h. SiCl₄(l) + 2H₂O(l) → 4HCl(aq) + SiO₂(s)

i. SiCl₄(l) + 2Mg(s) → 2MgCl₂(s) + Si(s)