Question

Explain chlor-alkali process. Why is it called so?

Answer 1

Hint:The process name reveals itself the products it forms. This is an electrolysis process where the chlorine and alkali i.e. sodium hydroxide are produced. One can elaborate on the process and also give a sufficient reason.

Complete step by step answer:1) First of all we will learn about the Chlor-alkali process where it is an industrial process in which electrolysis of sodium chloride solution is done. In this process generally, it is conducted on an aqueous solution of sodium chloride which gives sodium hydroxide, hydrogen, and chlorine as products.
2) In the case of using potassium chloride and calcium chloride the products consist of potassium and calcium respectively instead of sodium. For the completion of this process, there is a need for very high energy like to process a ton of sodium chloride there is a need for approximate $\text{2500 kWh}$ electricity.
3) The reaction of chlor-alkali process is as below,
$2NaCl+2H_{2}O\stackrel{}{\to }2NaOH+C{l}_2+H_2$
In the above reaction when $\text{2}$ moles of sodium chloride are reacted with $\text{2}$ moles of water there are $\text{2}$ moles of sodium hydroxide that are produced with one mole of each chlorine and hydrogen.
4) The products formed in the reaction are in the same proportion where two moles of sodium hydroxide are produced when one mole of chlorine is produced.
5) The word ‘Chlor’ means chlorine and the word ‘alkali’ stands for sodium hydroxide and hence the process is called the chlor-alkali process.

Note:The chlor-alkali process is also called electrolysis of brine. The brine is the cold and concentrated solution of sodium chloride. This process is used for the ${19}^{th}$ century and this process is used widely as the principal source of chlorine.