Redox

[H]

I need some help, how do I ajust this ecuation with redox method?

H₂S + NaCr₂O₇ + H₂SO₄ = Cr₂(SO₄)₃ + NaHSO₄ + S + H₂O


Thanks.

[H]

By the way, I already tried to use the app of here to ajust It, but It says "There's infinite ways to solve It" so im confused.

[ChenBeier]

Separate to redox parts

H₂S/ S and Cr₂O₇ 2- / Cr₃+

Oxidation: H₂S => 2 H+ + 2 e- + S

Reduction: Cr₂O₇ 2- + 14 H+ + 6 e- => 2 Cr₃+ + 7 H₂O

Balance electrons
3 H₂S => 6 H+ + 6 e- + 3 S

Addition

Cr₂O₇ 2- + 3 H₂S + 8 H+ => 2 Cr₃+ + 3 S + 7 H₂O

Add of Na+ and SO₄ 2-


Na₂Cr₂O₇ + 3 H₂S + 4 H₂SO₄ => Cr₂(SO₄)₃ + 3 S + Na₂SO₄ + 7 H₂O