Question

. In the electrolysis of brine (which is 40% aqueous solution of NaCl by mass) (ब्राइन के विद्युत अपघटन पर (जो NaCl का द्रव्यमान के आधार पर जलीय विलियन है)- (i) Hydrogen gas librated at cathode and chlorine gas librated at anode. (कैथोड पर हाइड्रोजन गैस व एनोड पर क्लोरीन गैस मुक्त होगी ) (ii) Hydrogen gas librated at anode and chlorine gas librated at cathode. (कैथोड पर क्लोरीन गैस व एनोड पर हाइड्रोजन गैस मुक्त होगी ) (iii) This is an example of endothermic reaction. (यह एक ऊष्माशोषी अभिक्रिया का उदाहरण है) (iv) This is an example of exothermic reaction. (यह एक ऊष्माक्षेपी अभिक्रिया का उदाहरण है) Which is the correct combination? (सही संकलन कौन सा है)

Answer 1

The correct options are:

• Hydrogen gas liberated at cathode and chlorine gas liberated at anode.
• This is an example of endothermic reaction.

• The reaction at the cathode is:

2H₂O + 2e⁻ → H₂ + 2OH⁻

• The reaction at the anode is:

2Cl⁻ → Cl₂ + 2e⁻

• The overall reaction is as follows:

2H₂O(l) + 2Cl⁻(aq) → H₂(g) + Cl₂(g) + 2OH⁻(aq)

The electrolysis of NaCl produces Cl₂ gas and H₂ gas at anode and cathode respectively. The electrolysis of brine is used in the industry on a large scale to make chlorine. The by products of this electrolysis include Sodium hydroxide (NaOH) and Hydrogen gas (H₂).

Answer 2

Given :

In the electrolysis of brine (which is 40% aqueous solution of NaCl by mass)

i) Hydrogen gas liberated at cathode and chlorine gas liberated at anode.

(ii) Hydrogen gas liberated at anode and chlorine gas liberated at cathode.

(iii) This is an example of endothermic reaction

(iv) This is an example of exothermic reaction

Which is the correct combination?

A)(1)& (iv)

B) (ii) & (111)

C) (11) & (iv)

D) (iii) &(1)​

correct answer : option D

Explanation:

Brine solution is a solution of Sodium Chloride in water.

When electricity is passed through a concentrated solution of Sodium Chloride called Brine it decomposes to form sodium Hydroxide , chlorine and hydrogen.

Chemical equation :

                                  Electrolysis

2 NaCl (aq ) + H2O  ----------------------->   2 NaOH (aq)  + Cl2(g)

During the electrolysis, the chlorine is released at anode and hydrogen gas at cathode(negative terminal)

So option 1 is correct and option iii [ as It takes in energy for decomposition in the form of Electrolysis.