Identify the substance oxidized reduced, oxidizing agent and a reducing agent for each of the following reactions:

HCHO (l) + 2 Cu²⁺ (aq) + 5 OH^– (aq) → Cu₂O(s) + HCOO^–(aq) + 3H₂O(l)

Oxidised substance:- HCHO

Reduced Substance:- Cu^{2 +}

Reducing agent:- HCHO

Oxidising agent:- Cu²⁺

Explanation:- Oxidising agent is a reagent which can increase the O.N. of an element in a given substance.

Cu^{+ 2} helps HCHO to increase its oxidation state.

The reduced substance is a reagent whose oxidation state has been decreased.

Here, in this case, Cu⁺² has + 2 oxidation state and the O.N. is reduced to + 1 as Cu⁺¹ in the product side is present in + 1 O.N.

The oxidised substance is a reagent whose oxidation state has been decreased.

Carbon in HCHO is present in zero oxidation state which is increased to + 2 in HCOO^-.

Reducing Agent is a reagent which lowers the oxidation number of an element in a given substance.

HCHO helps Cu⁺² to decrease its oxidation state.