A solution of Ni(NO3)2 is electrolysed between platinum electrodes using a current of 5 amperes for 20 minutes. What mass of Ni is deposited at the cathode?
Given
I=5A
Time=20×60=1200s
∴Charge=current×time
=5×1200
=6000C
According to the reaction.
Ni2+(aq.)+2e→Ni(s)
Nickeldepositeby(2×96487)C=58.7g
∴Nickeldepositeby 6000C=58.7×60002×96487
=1.825g
∴ Hence 1.825g of nickel will be deposited at the cathode.