Electrochemistry 1 Question 47
46. A 100 watt, $110 \mathrm{V}$ incandecent lamp is connected in series with an electrolyte cell containing cadmium sulphate solution. What weight of cadmium will be deposited by the current flowing for $10 \mathrm{h}$ ?
$(1987,5 \mathrm{M})$
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Answer:
Correct Answer: 46. $19.1 \mathrm{g}$
Solution:
- $100 \mathrm{W}$ lamp will produce $100 \mathrm{Js}^{-1}$.
$\Rightarrow \quad 100 \mathrm{J}=110 \times C \Rightarrow C=\frac{10}{11}$ Coulombs
Therefore, total Coulomb passed in $10 \mathrm{h}$
$ =\frac{10}{11} \times 10 \times 60 \times 60=32727.27 \mathrm{C} $
Number of gram equivalent of $\mathrm{Cd}^{2+}$ deposited
$ =\frac{32727.27}{96500}=0.34 $
Weight of $\mathrm{Cd}$ deposited $=0.34 \times \frac{112.4}{2} \mathrm{g}=19.1 \mathrm{g}$
