Identify the oxidizing agent and the reducing agent in the following reactions: (i) 8NH3 (g) + 6NO2 (g) = > 7N2 (g) + 12H2O (l) (ii) Zn (s) + AgNO3 (aq) = > Zn (NO3) 2 (aq) + Ag (s) (unbalanced)

(i) Oxidizing Agent: NO2 / Reducing Agent NH3-

(ii) Oxidizing Agent AgNO3 / Reducing Agent Zn

Explanation:

(i) 8NH3 (g) + 6NO2 (g) = > 7N2 (g) + 12H2O (l)

In this reaction, both two reactants contain nitrogen with a different oxidation number and produce only one product which contains nitrogen with a unique oxidation state. So, nitrogen is oxidized and reduced in the same reaction.

Nitrogen Undergoes a change in oxidation state from 4 + in NO2 to 0 in N2. It is reduced because it gains electrons (decrease its oxidation state). NO2 is the oxidizing agent (electron acceptor).

Nitrogen Changes from an oxidation state of 3 - in NH3 to 0 in N2. It is oxidized because it loses electrons (increase its oxidation state). NH3 is the reducing agent (electron donor)

(ii) Zn (s) + AgNO3 (aq) = > Zn (NO3) 2 (aq) + Ag (s)

Ag changes oxidation state from 1 + to 0 in Ag (s).

Ag is reduced because it gains electrons and for this reason and AgNO3 is the oxidizing agent (electron acceptor)

Zn Changes from an oxidation state of 0 in Zn (s) to 2 + in Zn (NO3) 2. It is oxidized and for this reason Zn is the reducing agent (electron donor).

Balanced equation:

Zn (s) + 2AgNO3 (aq) = > Zn (NO3) 2 (aq) + 2Ag (s)