Question
Which of the following statements is not correct regarding preparation of $$NaOH?$$
A.
$$NaOH$$ is prepared by electrolysis of sodium chloride in Castner - Kellner cell.
B.
Sodium metal discharged at cathode combines with mercury to form sodium amalgam.
C.
Chlorine is evolved at anode.
D.
Amalgam is heated to separate $$Na$$ and $$Hg.$$
Answer :
Amalgam is heated to separate $$Na$$ and $$Hg.$$
Solution :
Amalgam is treated with water to give sodium hydroxide and hydrogen gas.
$$2Na\,{\text{ - amalgam}} + 2{H_2}O \to $$ $$2NaOH + 2Hg + {H_2} \uparrow $$