10.27 State as to why (a) a solution of Na2CO3 is alkaline ? (b) alkali metals are prepared by electrolysis of their fused chlorides ? (c) sodium is found to be more useful than potassium ?

Answers (1)
R Rakesh

(a)  when sodium bicarbonate is added to water it gives sodium hydroxide (strong base). As a result, the solution becomes alkaline in nature.

Na_{2}CO_{3}+H_{2}O\rightarrow NaOH+ H_{2}CO_{3}

(b) Because their oxides are themselves are a very strong reducing agent in nature. So, by chemical reduction, we cannot obtain alkali metals. Also, we cannot use electrolysis of the aqueous solution method because after liberating the metals they again react with water.( 

(2M+H_{2}O\rightarrow 2M^{+}+2OH^{-}+H_{2}) [M = alkali metals]