Answer is: color.
Chemical reaction of dissociation of sodium chloride in water:
NaCl(aq) → Na⁺(aq) + Cl⁻(aq).
Small quantities of water are colorless, solution of sodium chloride is also colorless.
Adding sodium chloride to water change water melting and boiling points.
The boiling point of a substance is the temperature at which the vapor pressure of the liquid equals the pressure surrounding the liquid and the liquid changes into a vapor.
