Sodium chloride (NaCl) is a compound that is commonly known as table salt. It is a crystalline solid containing a molar mass of 35.45 g/mol and dissociates into two ions, Na+ and Cl-. The boiling point of NaCl is 1465 degrees Celsius. If all of the water in a boil were removed, NaCl would recombine to form a solid salt.
NaCl’s boiling point is a result of its strong ionic interaction. When sodium chloride is dissolved in water, its ions are surrounded by six Cl- ions. This ion-dipole interaction helps to stabilize the crystallographic structure. There are a variety of ionic compounds that are organized in similar crystalline structures. However, some of these compounds decompose before boiling. Solutes in a solution have a lower vapor pressure than a pure solvent. They require higher temperatures to equalize the vapor pressure.
Adding a solute to a solvent increases the boiling point of the solution. Because of the ionic bond, determining the boiling point of ionic crystals is difficult. Some reference sources provide the temperature required to dissolve the solute.
The molal boiling point elevation constant has several different values depending on the identity of the solvent. For example, methanol has the highest molal boiling point elevation constant, while sugar has the lowest.
The boiling point of water increases with the addition of sodium. For every 58 grams of dissolved salt per kilogram of water, the boiling point increases by 0.5 degrees Celsius.