Solve it 

Asked by g_archanasharma | 22nd Mar, 2018, 10:11: PM

Expert Answer:

For balancing a redox reaction, you have to balance the no. of atoms on reactant and product side i.e, no. of atoms on both sides should be equal.
 
C u O space plus space N H subscript 3 space end subscript space rightwards arrow with blank on top space C u space plus space N subscript 2 space plus space H subscript 2 O
no.of Hydrogen atoms are not equal on both sides.
 
C u O space plus 2 space N H subscript 3 space end subscript space rightwards arrow with blank on top space C u space plus space N subscript 2 space plus 3 space H subscript 2 O
In CuO the oxidation no. of Cu is +2 while in Cu its 0 that means Cu gets reduced,
 
and in NH3 Oxidation no of N is -3 and in the product, it produced N2 with 0 oxidation no. hence it gets oxidised 
 
There is no change in the O.S. of oxygen. lets balanced it by multiplying CuO by 3 we get,
 
3 C u O space plus 2 space N H subscript 3 space end subscript space rightwards arrow with blank on top space 3 C u space plus space N subscript 2 space plus 3 space H subscript 2 O

Answered by Ramandeep | 23rd Mar, 2018, 09:26: AM