• NaCl • CaCl 2 • Glucose • Electrolytes break apart into ions. Each ion has an effect on boiling point and freezing points. If a solution has more ions it will change the boiling points and melting points even more.
Freezing Point Depression
Example • Salt is added to melt ice by reducing the freezing point of water.
Did you know? • Some animals are able to survive freezing temperatures by producing natural antifreezes, substances that lower the freezing point of a liquid. In many freeze-tolerant insects, the antifreezes are alcohols and sugars. • Examples are box turtles, painted turtles and garter snakes, sugar maples and white spruce.
Boiling Point Elevation • The boiling point of a liquid is the temperature at which the vapor pressure of the liquid is equal to the prevailing atmospheric pressure. • Vapor pressures of solutions containing nonvolatile solute is lower than the vapor pressure of the pure solvent.
• This means that more heat will be required to raise the vapor pressure of the solution. Thus, the boiling point of a solution is higher than the boiling point of the pure substance.
Example • Addition of ethylene glycol C 2 H 6 O 2 (antifreeze) to car radiators.
- Fall '16
- Mr. grady
- Solubility, Vapor pressure, Freezing-point depression