Question

Balance the redox reaction in acid solution

SHOW WORK

P+Cu2+-->Cu+H2PO4

Answer 1

P in P has oxidation state of 0

P in H2PO4 has oxidation state of +6

So, P in P is oxidised to H2PO4

Cu in Cu+2 has oxidation state of +2

Cu in Cu has oxidation state of 0

So, Cu in Cu+2 is reduced to Cu

Reduction half cell:

Cu+2 + 2e- --> Cu

Oxidation half cell:

P --> H2PO4 + 6e-

Balance number of electrons to be same in both half reactions

Reduction half cell:

3 Cu+2 + 6e- --> 3 Cu

Oxidation half cell:

P --> H2PO4 + 6e-

Lets combine both the reactions.

3 Cu+2 + 1 P --> 3 Cu + 1 H2PO4

Balance Oxygen by adding water

3 Cu+2 + 1 P + 4 H2O --> 3 Cu + 1 H2PO4

Balance Hydrogen by adding H+

3 Cu+2 + 1 P + 4 H2O --> 3 Cu + 1 H2PO4 + 6 H+

This is balanced chemical equation in acidic medium

Answer:

3 Cu²⁺ + P + 4 H₂O --> 3 Cu + H₂PO₄ + 6 H⁺