(Sorry typed in wrong )Balance this ionic equation for a redox reaction, using only whole number coefficients?

Question

Balance this ionic equation for a redox reaction, using only whole number coefficients?

? MnO4^- (aq) + ? Fe^+2 (aq) + ? H3O^+ (aq) --------> ?Mn^+2 (aq) + Fe^+3 (aq) + ?H2O (l)

What is the coefficient for Fe^+2 in the balanced equation?

Please provide me the solution for this type of question (even though I understand how to balance, but can't do nothing with this sort of problem)

Also another similar problem

? Cr2O7^-2 + ?H2S (aq) -> ? Cr^+3 (aq) + ?S(s)

Answer 1

MnO4- (Mn is +7) --> Mn^+2 (gain of 5 electrons)

Fe^+2 --> Fe^+3 (loss of 1 electron)

electron gain/loss must be balanced

need 5Fe^2 --> 5Fe^3 for every 1 MnO4^-1 --> Mn^+2

MnO4^-1 + 5Fe^+2 + 8H3O^+1 --> 5Fe^+3 + Mn^+2 + 12H2O

Cr2O7^-2 (Cr+6) --> 2Cr^+3 (a gain of 2x3=6 electrons)

H2S (S-2) --> S (a loss of 2 electrons)

Cr2O7^-2 + 3H2S + 8H^+1 --> 2Cr^+3 + 3S + 7H2O