Question
Balance the following equation:
Solution
(i) The skeleton equation along with O.N. of each atom is
(ii) Noting the change in O.N. of the above atoms,
Increase Cr = +3 to +6 i.e. 3
Decrease 1 = +5 to -1 i.e. 6
(iii) Balancing the total increase in O.N. with a total decrease in O.N. by multiplying Cr(OH)3 by 2.
(iv) Balance Cr atoms by multiplying 
by 2.
(v) Balance O atoms by adding OH- ion on the R.H.S.
(vi) Balance H atoms by adding H2O and OH- ions as,
