State as to why
(a) a solution of `Na_(2)CO_(3)` is alkaline ?
(b) alkali metals are prepared by electrolysis of their fused chlorides?
(c) sodium is found to be more useful than potassium ?

Explanation

The biological functions of sodium are much more important than those of potassium. Sodium ions help in the transmission of nerve signals, in the transport of water across the cell membranes and in the transport of sugars and amino acids into the cells. They exist in blood plasma surrounding the cells. Potassium ions are present in the cell fluids. Although `K^(+)` ions also play an important role in biological systems, yet the role of sodium ions is more important. This is why sodium is more useful than potassium.