a. `Na_(2)CO_(3)` is a salt of a weak acid, carbonic acid `(H_(2)CO_(3))` and a strong base sodium hydroxide `(NaOH)`. Therefore, it undergoes hydrolsis to produce strong base `NaOH` and hence its aqueous solution is alkaline in nature.
`Na_(2)CO_(3(s))+H_(2)O_((l))rarrunderset("Strong base")(2NaOH_(aq))+underset("weak acid")(H_(2)CO_(3(aq)))`
b. Since the discharge potential of alkali metals is much higher than that of hydrogen, therefore, when the aqueous solution of any alkali metal chloride is subjected to electrolysis. `H_(2)` instead of the alkali metal is produced at the cathode. Therefore, to prepare alkali metals, electrolysis of their fused chlorides is carried out.
c. Sodium ions are found primarily in the blood plasma and in the interstitial fluid which surrounds the cells while potassium ions are present within the cell fluids. Sodium ions help in the transmission of never signals, in regulating the flow of water across cell membrances and in the transport of sugars and amino acids into the cells. Thus, sodium is found to be more useful than potassium.
