Question

How to solve this redox reaction?

Ni3O4 + HCl => NiCl2 + H2O + Cl2

How to solve this redox reaction using partial reaction method?

Answer 1

Reduction involves gaining electrons from a species that was oxidized (e.g. lost electrons). We calculate these through oxidation states, which I've omitted for clarity.

We'll divide it into oxidation and reduction reactions, and balance each in turn, making sure to keep the electrons transferred constant, as well. Hence,

`Ni_3O_4 + HCl to NiCl_2 + H_2O + Cl_2`

Will divide into,

`2H^(+)+Ni_3O_4 + 6HCl + 2e^(-) to 3NiCl_2 + 4H_2O`

`2HCl to Cl_2 + 2H^(+) + 2e^(-)`

Now we'll add these things,

`2HCl to Cl_2 + 2H^(+) + 2e^(-)`
`2H^(+)+Ni_3O_4 + 6HCl + 2e^(-) to 3NiCl_2 + 4H_2O`
`------------------`

`8HCl + Ni_3O_4 to Cl_2 + 3NiCl_2 + 4H_2O`

Voila!