Zn + H2SO4 ==> ZnSO4 + H2S + H2O
Zn changes from 0 on the left to +2 on the right for loss of 2e.
S changes from +6 on the left in SO4^2- to -2 on the right for gain of 8e.
(S in SO4 also is on the left and right unchanged but we take care of that later)
So we multiply Zn by 4 (to make 4 x 2 = 8e and H2SO4 by 1 (to make 1 x 8 = 8e gained) this way.
4Zn + 1H2SO4 ==> 4ZnSO4 + 1H2S + H2O
That takes care of the redox part. Zn is OK but we have added 4 SO4^2- on the right from the 4ZnSO4 so we need to add 4 more H2SO4 to balance the non-redox part this way.
4Zn + 5H2SO4 ==> 4ZnSO4 + 1H2S + H2O
Then finish balancing by inspection.
4Zn + 5H2SO4 ==> 4ZnSO4 + H2S + 4H2O
Done but note that this is not the USUAL rxn with Zn and H2SO4.
The products of the reaction between zinc and sulfruric acid are zinc sulfate, hydrogen sulfide, and water. Balance the equation using the electron-transfer method
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