BALANCING REDOX doubt

for 1st , after writing step 2 ,

u shud write the respective compounds of the species that are in step 2 only ,
for 3S⁶⁺ & 2Cr³⁺ , as they are in the same compound, u shud write that compound only ,bcz if u would hav written Na₂SO₄ , then while balancing Na atoms, u will be adding Na₂CrO₄ , but since Cr is already balanced , u shud not do that .
so
3SO₂ + 2Na₂CrO₄ → Cr₂(SO₄)₃

now balance Na atoms

3SO₂ + 2Na₂CrO₄ → 2Na₂SO₄ + Cr₂(SO₄)₃

now using H₂SO₄ balance SO₄ grp of 2Na₂SO₄ only bcz u already balanced sulphur atoms of Cr₂(SO₄)₃ while balancing with e^-

so
3SO₂ + 2Na₂CrO₄ + 2 H₂SO₄ → 2Na₂SO₄ + Cr₂(SO₄)₃

balance H now and check if O atoms are also getting balanced simultaneously

3SO₂ + 2Na₂CrO₄ + 2 H₂SO₄ → 2Na₂SO₄ + Cr₂(SO₄)₃ + 2H₂O

2.
C^2- → C²⁺ + 4e^-

I₂ + 2e^- → 2 I^-

so C^2- + 2 I₂ → C²⁺ + 4I^-

multiply by 2

2C^2- + 4 I₂ → 2 C²⁺ + 8I^-

i.e

2C^2- + 4 I₂ → (C²⁺ + 3I^- ) + C²⁺ + 5 I^-

write CHI₃ for (C²⁺ + 3I^- ) , HCO₂^- for C²⁺,

so

C₂H₅OH + 4 I₂ → CHI₃ + HCO₂^- + 5 I^-

balance charge using OH^-

C₂H₅OH + 4 I₂ + 6OH^- → CHI₃ + HCO₂^- + 5 I^-

now balance O atoms using H₂O

C₂H₅OH + 4 I₂ + 6OH^- → CHI₃ + HCO₂^- + 5 I^- + 5 H₂O