[potatopotato]

First problem - add H+ ions as needed to balance charge; add H2O as needed to balance H atoms.

H2O2 + (Cr2O7)-2 --> Cr+3 + O2

Problem 2 - add OH- ions as needed to balance charge; then add H2O as needed to balance H atoms.

(HO2)- (note: peroxide ion) + (CrO2)- --> (CrO4)-2

Can someone explain the procedures to balancing the equations please?? Thx

[ARGOS++]

Dear potatopotato;

There is no real difference for balancing to a “normal” Rx-Equation, except that you have finally also to balance the number of electrons (See electrons as an additional Component.).

So you may follow the links for balancing in:  "Stoichiometry Problem (#23’025)”
And finally see also on:  "Balancing a RedOx”

I hope it may be of help to you.
Good Luck!
                    ARGOS⁺⁺

[AWK]

Start from Borek primer
http://www.chembuddy.com/?left=balancing-stoichiometry&right=balancing-redox