Question

During electrolysis of an aqueous solution of $C{u}^{2+}$ sulphate, $0.635g$ of copper was deposited at cathode. The amount of electricity consumed in coulomb is:

• A. $1930$
• B. $3860$
• C. $9650$
• D. $4825$

Answer 1

Answer: (A)

$1930$

To deposit $1$ $mole$ of copper $2$ Farads of electricity is needed.

$⟹C{u}^{2+}+2e^{-}⟶Cu$

Given, $0.635$ $g$ deposited

$⟹$ No. of moles of copper deposited $=\frac{0.635}{63.5}=0.01$ $moles$

$1$ $mole-2$ $Farads$

$0.01$ $mole-0.02$ $Farads$

$1$ $Farads=96500$ $Coulomb$

$0.02$ $Farad=0.02\times 96500=1930$ $Coulomb$