Question

(a) Explain ‘Kohlrausch law of independent migration of ions’ with suitable examples

(b) A solution of $CuS{O}_4$ is electrolysed for 10 minutes with a current of 1.5 amperes. What is the mass of copper deposited at the cathode?

Answer 1

(a) Kohlrasch law of independent migration of ions:-

The limiting molar conductivity of an electrolyte can be represented as the sum of the individual contribution of the anion and cation of the electrolyte.

${\lambda }_{m\left(NaCl\right)}^{\circ }={\lambda }_{N{a}^{+}}^{\circ }+{\lambda }_{C{l}^{-}}^{\circ }$

(b) $Q=it$
$t=10min=10\times 60sec$
$i=1.5amperes$
$Q=600\times 1.5=900C$
$96,500Cdeposits=\frac{63}{2}gofCu=31.5$
$900Cwilldeposit=\frac{900\times 31.5}{96.500}=0.299$