How Does Salt Aid In Conducting Electricity Through Water?

A salt is formed by the neutralization of a base and an acid. A positive charged ion and a negative charged ion are combined to form a salt. When a salt is added to water, it decomposes into its cation and anion. Electricity passes through a substance due to the flow of free ions or free charge carrier. Salt water solution has free ions therefore, salt dissolved in water can conduct electricity. For example when sodium chloride is dissolved in water, it can conduct electricity.

Salt is the general name of the chemical compound called sodium chloride, sodium compound is an ionic compound being produced by the chemical bonding of sodium ion and chloride ion. Sodium has eleven electrons and has one extra electron in its outer most shell and chlorine runs short of one electron. As sodium losses one electron chlorine gains it and a chemical bond is produced.

So due to its ionic nature it is a polar compound. Water on the other hand is a compound produced by covalent bonding of hydrogen and oxygen. However water is non polar in nature. It has oxygen and hydrogen which is different in electronegativities due to difference in electronegativities temporary dipoles or partial charges are produced which will cause an attraction between hydrogen and oxygen causing hydrogen bonding. This hydrogen bonding does not allow electricity to flow through it.

In order to electrolyze water a lot of electric potential is required. If any polar compound like sodium chloride is added into water it will easily disperse and allow free flow of charged particles which will support the flow of current through the circuit. Thus addition of salt actually adds some polar groups in the non polar water which will easily flow through the solution and will help increasing the flow of current through water.