What is the effect of adding salt to water on its specific gravity?

When salt is added to water, it increases the mass of the liquid without significantly changing its volume. Specific gravity is defined as the ratio of the density of a substance to the density of a reference substance, commonly water for liquids. Since the density of a solution increases with the addition of salt, the specific gravity also increases.

This happens because salt (sodium chloride) has a higher density than water. When salt dissolves, it dissociates into sodium and chloride ions, increasing the total mass of the solution. The added mass from the salt increases the density of the water-salt mixture, resulting in a higher specific gravity compared to pure water.

Therefore, the correct answer highlights that the addition of salt to water increases its specific gravity due to the increase in density from the dissolved salt.