An acidic solution of `Cu^(2+)` salt contaning `0.4` of `Cu^(2+)` is electrolyzed untill all the copper is deposited. The electrolysis is continued for seven more minutes with the volume of solution kept at 100mL and the current at `1.2` amp. Calculate the volume of gases evolved at NTP during the entire electrolysis.

Explanation

`0.4 g` of `Cu^(2+)=0.4/31.75=0.0126 g`- equivalent
At the same time, the oxygen deposited at anode
`=0.0126 g` - equivalent
`=8/32xx0.0126=0.00315 g`-mole
After the complete deposition of copper, the electrolysis will dicharge hydrogen cathode and oxygen at anode.
The amount of charge pased `=1.2 xx 7xx60=504` coulomb So, Oxygen liberated `=1/96500xx504=0.00523 g`-equivalent
`=8/32xx0.00523=0.001307 g`-mole
Hydrogen linderated `=0.00523 g`- equivalent
`=1/2 xx0.00523=0.00261 g`- mole
Total gases evolved `=(0.00315+0.001307+0.00261)g`- mole
`=0.007067 g`- mole
Volume of gases evolved at NTP
`=22400xx0.007067 mL`
`=158.3 mL`