Question

Balance the equation using oxidation number method.

Cr3+ + Na2O2 -------- CrO4- + Na+

Answer 1

Hi friend,

The balancing equation is:-

Cr3+ 6Na2O2= 3 Cro4 + 12 Na...i hope it helps you

Answer 2

Answer :

The half reactions are,

(1) $Cr^{3+}+4H_2O\rightarrow CrO_4^-+8H^++e^-$

(2) $Na_2O_2+4H^++2e^-\rightarrow 2Na^++2H_2O$

For balancing the electrons, multiple the equation 1 by 2 and then adding equation 1 and 2, we get balanced equation.

The overall reaction follows:

$2Cr^{3+}+6H_2O+Na_2O_2\rightarrow 2CrO_4^-+12H^++2Na^+$

Hence, the equations required are given above.