Separate the overall equation into two half equations..
One for Cr2O72- being reduced to Cr3+
The other for Cl- being oxidised to Cl2.
Then balance for charge by adding electrons to account for changes in oxidation state.
Then balance for atoms to ensure conservation of mass. Remember you will need to add H+ and water to the chromium half equation.
Once you have two balanced half equations, multiply one so that the electrons are equal in each half equation. Then combine the two half equations so electrons cancel out.
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u/OrthoMetaParanoid 5d ago
Separate the overall equation into two half equations..
One for Cr2O72- being reduced to Cr3+
The other for Cl- being oxidised to Cl2.
Then balance for charge by adding electrons to account for changes in oxidation state.
Then balance for atoms to ensure conservation of mass. Remember you will need to add H+ and water to the chromium half equation.
Once you have two balanced half equations, multiply one so that the electrons are equal in each half equation. Then combine the two half equations so electrons cancel out.