Which of these equations does not represent an oxidation-reduction reaction?

a. 3Al + 6HCl → 3H2 + AlCl3

b. 2H2O → 2H2 + O2

c. 2NaCl + Pb (NO3) 2 → PbCl2 + 3NaNO3

d. 2NaI + Br2 → 2NaBr + I2

c. 2NaCl + Pb (NO3) 2 → PbCl2 + 3NaNO3

Explanation:

In the others the elements change their oxidation number when they convert in products. In this reaction no.

Reagents

NaCl = Na (+1), Cl (-1)

PB (NO3) 2 = Pb (+2), N (+5), O (-2)

Products

PbCl2 = Pb (+2), Cl (-1)

NaNO3 = Na (+1), N (+5), O (-2)