Question

Which of these reactions IS NOT a reduction-oxidation reaction?

I. 2Na (s) + 2H2O(l)  2NaOH(s) + H2 (g)

II. AgNO3 (aq) + NaCl (aq)  AgCl (s) + NaNO3 (aq)

III. 6Na (s) + Fe2O3 (s)  3Na2O (s) + 2Fe (s)

IV. HNO3 (aq) + KOH (aq)  KNO3(aq) + H2O (aq)

V. CH4 (g) + 2O2 (g)  CO2 (g) + 2H2O (g)

a. I and II

b. II and III

c. III and IV

d. II and V

e. II and IV

Can you also explain why? I'm having a really hard time understanding all of this. Thank you!

Answer 1

reduction - oxidation reaction is where both oxidation reduction takes place.

e. II and IV

II. AgNO3 (aq) + NaCl (aq)  AgCl (s) + NaNO3 (aq)

in this reaction A is +1 state in both reactant side and product side,

same way Na also +1 in both reactant and product side

Cl is in -1 state. so no oxidation reduction takes place . so it is not oxidation-reduction reaction.

IV. HNO3 (aq) + KOH (aq)  KNO3(aq) + H2O (aq)

it is simple acid-base reaction.

no oxidation-reduction takes place.