Question

List the important products of the Chlor-Alkali process. Write one important use of each.

Answer 1

Hint: The cold and concentrated solution of Sodium Chloride is electrolysed to give three products which are sodium hydroxide, Chlorine gas and Hydrogen gas. All these products are collected separately and each of these finds a variety of applications in industrial and commercial purposes.

Complete step by step answer:
The cold and concentrated solution of Sodium chloride, $$NaCl$$ is called Brine. When brine is electrolysed, then three products are formed, sodium hydroxide ( $$NaOH$$ ), Chlorine gas ( $$C{l}_2$$ ) and Hydrogen gas ( $$H_2$$ ). Since the process is electrolysis, we have cathode, anode and electrolyte.
Here, electrolyte is the Brine solution. Chlorine gas is formed at anode, hydrogen gas is formed at cathode while sodium hydroxide remains in solution or electrolyte form. The reaction can be written as:

$$2NaCl+2H_{2}O\stackrel{Electricity}{\to }2NaOH+C{l}_2+H_2$$

Thus, each of these products has a variety of uses and applications in industrial as well as commercial purpose. The uses are listed below:

Uses of Sodium hydroxide ($$NaOH$$ ):
1. For manufacturing of soaps and detergents in industry.
2. In the manufacturing of papers in paper mills
3. In the textile industry to process rayon as artificial fibres.

Uses of Chlorine gas ($$C{l}_2$$ ):
1. Used as disinfectant when made into bleaching powder.
2. In manufacturing of Hydrochloric acid, HCl, which is very important for industries.
3. Manufacture of pesticides
4. Manufacture of plastics like PVC, poly vinyl chloride
5. Paints manufacturing also involves Chlorine gas.

Uses of Hydrogen gas ($$H_2$$ ):
1. It is clean fuel, used in rockets and other places.
2. In industries for hydrogenation of substances like vegetable oil to vegetable ghee.
3. In manufacture of ammonia, $$N{H}_3$$ which can be used in fertilisers.

Note: This process is called Chlor-alkali process due to its products formed. Chlor is for chlorine which is one of the products formed, and alkali is for sodium hydroxide, which is dissolved base in solution, which is remaining after electrolysis.
In electrolysis, the products are obtained at cathode and anode. The products are gases, so we should be careful in collecting these gases, which are by-products of the chlor-alkali process.
Remember to use a cold and concentrated solution of NaCl, sodium chloride. As if the solution is dilute then the products will change.