An electric current is passed through silver nitrate solution using silver electrodes. $$15.28\,g$$ of silver was found to be deposited on cathode. What will be
the weight of copper deposited on cathode if same amount of electricity is passed through copper sulphate solution using copper electrodes?
A.
4.49 $$g$$
B.
6.4 $$g$$
C.
12.8 $$g$$
D.
3.2 $$g$$
Answer :
4.49 $$g$$
Solution :
Equivalent $$wt.$$ of $$Ag = \frac{{108}}{1} = 108$$
Equivalent $$wt.$$ of $$Cu = \frac{{63.5}}{2} = 31.75$$
$$\frac{{{\text{Eq}}.\,wt\,{\text{of}}\,\,Ag}}{{{\text{Eq}}.\,wt.\,{\text{of}}\,\,Cu}}$$ $$ = \frac{{{\text{Mass of }}Ag{\text{ deposited}}}}{{{\text{Mass of }}Cu{\text{ deposited}}}}$$
$$\frac{{108}}{{31.75}} = \frac{{15.28}}{W} \Rightarrow W$$ $$ = \frac{{15.28 \times 31.75}}{{108}} = 4.49\,g$$
Releted MCQ Question on Physical Chemistry >> Electrochemistry
Releted Question 1
The standard reduction potentials at $$298 K$$ for the following half reactions are given against each
$$\eqalign{
& Z{n^{2 + }}\left( {aq} \right) + 2e \rightleftharpoons Zn\left( s \right)\,\,\,\,\,\,\,\,\, - 0.762 \cr
& C{r^{3 + }}\left( {aq} \right) + 2e \rightleftharpoons Cr\left( s \right)\,\,\,\,\,\,\,\,\, - 0.740 \cr
& 2{H^ + }\left( {aq} \right) + 2e \rightleftharpoons {H_2}\left( g \right)\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,0.000 \cr
& F{e^{3 + }}\left( {aq} \right) + 2e \rightleftharpoons F{e^{2 + }}\left( {aq} \right)\,\,\,\,\,\,\,\,0.770 \cr} $$
which is the strongest reducing agent ?
A solution containing one mole per litre of each $$Cu{\left( {N{O_3}} \right)_2};AgN{O_3};H{g_2}{\left( {N{O_3}} \right)_2};$$ is being electrolysed by using inert electrodes. The values of standard electrode potentials in volts (reduction potentials) are :
$$\eqalign{
& Ag/A{g^ + } = + 0.80,\,\,2Hg/H{g_2}^{ + + } = + 0.79 \cr
& Cu/C{u^{ + + }} = + 0.34,\,Mg/M{g^{ + + }} = - 2.37 \cr} $$
With increasing voltage, the sequence of deposition of metals on the cathode will be :