First slide

Electrolysis

Question

When aqueous sodium chloride solution is electrolysed

Easy

A

at cathode H⁺ is reduced into H₂ instead of Na⁺
B

at cathode Na⁺ is reduced to Na
C

Cl^- is oxidised into Cl₂ at cathode
D

Both (b) and (c)

Solution

When aqueous solution of NaCl is electrolysed, there is a competition between the following reductions reactions at cathode
$\begin{array}{r} {Na}^{+} + e^{-} ⟶ Na; E_{cell}^{\circ} = - 2 .71 V \\ H^{+} + e^{-} ⟶ \frac{1}{2} H_{2}; E_{cell}^{\circ} = 0 .00 V \end{array}$
The reaction with higher value of E^o is preferred and therefore, the second reaction occurs at cathode, i.e. H⁺ is reduced instead of Na⁺ .

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App