Electrochemistry - Result Question 2
####2. A solution of $Ni\left(NO _3\right) _2$ is electrolysed between platinum electrodes using 0.1 Faraday electricity. How many mole of $Ni$ will be deposited at the cathode? (2019 Main, 9 April II)
(a) 0.20
(b) 0.10
(c) 0.15
(d) 0.05
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Answer:
Correct Answer: 2. (b)
Solution:
- A solution of $Ni\left(NO _3\right) _2$ is electrolysed between platinum electrodes using 0.1 Faraday electricity. It means that 0.1 equivalent of $Ni^{2+}$ will be discharged.
Electrolysis of $Ni\left(NO _3\right) _2$ gives
$$ Ni^{2+}+2 e^{-} \longrightarrow Ni \quad(\text { Atomic mass of } Ni=58.7) $$
Number of equivalents $=$ Number of moles $\times$ number of electrons. $0.1=$ Number of moles $\times 2$
$\therefore$ Number of moles of $Ni=\frac{0.1}{2}=0.05$
