Question

What are the oxidizing agents, and the reducing agents for 2Na(aq)+2H2O(l)→2NaOH(aq)+H2(g)
C(s)+O2(g)→CO2(g)
2MnO−4(aq)+5SO2(g)+2H2O(l)→2Mn2+(aq)+5SO2−4(aq)+4H+(aq)

Answer 1

1.) 2Na(aq)+2H2O(l)→2NaOH(aq)+H2(g),

Na is oxidizing agent and H is reducing agent.

2.) C(s)+O2(g)→CO2(g)

C is an oxidizing agent

3.) 2MnO−4(aq)+5SO2(g)+2H2O(l)→2Mn2+(aq)+5SO2−4(aq)+4H+(aq)

Mn is reducing agent and S is oxidizing agent.

Answer 2

Answer :

(1) 'Na' act as a reducing agent and 'H' act as a oxidizing agent.

(2) 'C' act as a reducing agent and 'O' act as a oxidizing agent.

(3) 'S' act as a reducing agent and 'Mn' act as a oxidizing agent.

Explanation :

Reducing agent : It is defined as the agent which helps the other substance to reduce and itself gets oxidized. Thus, it will undergo oxidation reaction.

Oxidizing agent : It is defined as the agent which helps the other substance to oxidize and itself gets reduced. Thus, it will undergo reduction reaction.

(1) $2Na+2H_2O(l)\rightarrow 2NaOH(aq)+H_2(g)$

In this reaction, 'Na' is oxidized from oxidation (0) to (+1) and 'H' is reduced from oxidation state (+1) to (0). Hence, 'Na' act as a reducing agent and 'H' act as a oxidizing agent.

(2) $C(s)+O_2(g)\rightarrow CO_2(g)$

In this reaction, 'C' is oxidized from oxidation (0) to (+4) and 'O' is reduced from oxidation state (0) to (-2). Hence, 'C' act as a reducing agent and 'O' act as a oxidizing agent.

(3) $2MnO_4^-(aq)+SO_2(g)+2H_2O(l)\rightarrow 2Mn^{2+}(aq)+5SO_4^{2-}(aq)+4H^+(aq)$

In this reaction, 'S' is oxidized from oxidation (-4) to (0) and 'Mn' is reduced from oxidation state (+4) to (+2). Hence, 'S' act as a reducing agent and 'Mn' act as a oxidizing agent.