Balance the following equations using either the halfreactio

Balance the following equations, using either the half-reaction method or the oxidation number method Al + SO4 -- Al+3 + SO2

Solution

       Al + SO4-2 -------------- AL+3 + SO2

     0 +6                        +3       +4

Oxidation half reaction

Al ------------- Al+3

Al ------------ AL+3 + 3e-

Reduction half reaction

SO4-2 ------------- SO2

SO4-2 ------------ SO2 + 2 H2O

SO4-2 + 4 H+ ------------- SO2 + 2 H2O

SO4-2 + 4 H+ + 2e- --------------- SO2 + 2 H2O

[ Al ---------- ----------- Al+3 + 3e-] x2

[SO4-2 + 4 H+ +2e- --------- SO2 + 2 H2O]x3

2 Al --------------- 2 Al+3 + 6e-

3 SO4-2 + 12 H+ + 6e- ------------- 3 SO2 + 6 H2O

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2 Al + 3 SO4-2 + 12 H+ --------------- 2 Al+3 + 3 SO2 + 6H2O

This is the net balanced eqaution by half reaction method in acidic medium.