How do you balance these redox reactions by the half-reaction method?

Question

How do you balance these redox reactions by the half-reaction method?

Na + Hg2Cl2 → NaCl + Hg

Answer 1

You should be getting the hang of these by now. I've shown you how to do a bunch of them. I'll do part of this and see if you can finish it.

Na + Hg₂Cl₂ ==> NaCl + Hg

Na goes from zero oxidation number to 1+ so it has been oxidized

Na ==> Na⁺ (Cl is omitted as it is a spectator)

Na ==> Na⁺ +e- ... balanced for Na and charge and is the final balanced oxidation half reaction

Hg goes from 1+ oxidation state to zero so it has been reduced

2Hg⁺ + 2e- ==> 2Hg (Cl is omitted as a spectator) ... final balanced reduction 1/2 reaction

multiply the oxidation half reaction by 2 to equalize the electrons and add the two half reactions together. Combine and/or cancel like terms to get the final balanced redox equation. You can add back the Cl if needed