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Electrochemistry — Chemistry STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceChemistryElectrochemistry2 Marks
Question
A solution of $Ni(NO_3)_2$ is electrolysed between platinum electrodes using a current of $5$ amperes for $20$ minutes. What mass of $Ni$ is deposited at the cathode?
✓

Answer

Given,
Current $= 5A$
Time $= 20 \times 60 = 1200\ s$
Therefore, Charge $=$ current $\times$ time
$= 5 \times 1200$
$= 6000\ C$
According to the reaction,
$\text{Ni}^{2+}_\text{(aq)}+2\text{e}^-\rightarrow\text{Ni}_\text{(s)}\\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 58.7\text{g}$
Nickel deposited by $2 × 96487\ C = 58.71g$
Therefore, nickel deposited by $6000\ C =\frac{58.71\times6000}{2\times96487}\text{g}$
$= 1.825g$
Hence, $1.825g$ of nickel will be deposited at the cathode.

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