∵2F amount of charge give =1mol of Zn2+ ions. or, 2×96500C amount of charge give =1 mole of Zn2+ ions. ∴2×10−5C charge will give =
2×10−5
2×96500
(mole of Zn2+ ions) Amount of Zn2+(n) ions =1.0×10−5 Also n=
w
M
where n= number of moles w= mass of Zn2+ ions M= molar mass of Zn2+(65.5) ∴ w=n×M=1.00×10−5×65.5(M molar Zn2+=65.5) =65.5×10−5g 65.5×10−5×103 milligram. =0.65≈0.64 milligram of Zn2+ ions.