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BOILING POINT ELEVATION PROBLEMS
1. What is the boiling point elevation when an ammonia solution has a molality is 3.35
m? (solvent is water)
2. What is the molality of benzoic acid if the boiling point increases by 4.00˚C? (solvent
is water)
3. If urea is dissolved in chloroform and the molality is 1.35 m, what is the elevation in
boiling point?
4. What molality is needed to raise the boiling point of benzene by 2.10˚C?
5. Ethylene glycol is dissolved in water. If the molality is 15.3 m, what is the elevation
in boiling point?
6. If the boiling point of carbon tetrachloride must be raised by 10.2˚C, what must the
molality be?
7. Menthol is dissolved in acetic acid. What is the boiling point elevation when the
molality is 0.781 m?
8. Picolinic is dissolved in acetic acid. How much will the boiling point of acetic acid be
raised if the molality is 1.02 m?
9. Styrene glycol is a plasticizer, and is dissolved in benzene. What molality of benzene
must be used to raise the boiling point by 8.57˚C?
10. What is the boiling point elevation when the dye magenta-I is dissolved in ethanol,
and the molality is 0.0597 m?
FREEZING POINT DEPRESSION PROBLEMS
1. Silver is dissolved in ethanol to lower the freezing point. What molality of ethanol
must be used to decrease the temperature by 0.25˚C?
2. Oxygen gas is dissolved in water to lower the freezing point. If the molality of water
is 1.78 m, what is the freezing point depression?
3. Ethylene glycol (C2H6O2) is the principal ingredient in antifreeze. What molality of
ethylene glycol solution will be needed to lower the freezing point of water by 20˚C?
4. Diphenyl is dissolved in benzene to lower the freezing point by 3.20˚C. What is the
molality of the benzene?
5. Perylene is a constituent of coal tar and dissolved in chloroform. What molality of
chloroform must dissolved used in order to lower the freezing point by 2.75˚C?
6. How much will the freezing point of benzene be lowered 0.239 m benzene solution
is used?
7. What will the freezing point depression be if ibuprofen is dissolved in naphthalene?
The molality of naphthalene is 0.0199 m.
8. The pharmaceutical drug scopolamine is dissolved in water to lower water’s
freezing point. How much will the freezing point be lowered if the molality of water
is 0.878 m?
9. Pyrazole must be added to the solvent, benzene, to lower the freezing point by
5.00˚C. What molality of benzene solution must be used?
10. If you lower the freezing point of chloroform by 2.50˚C, how what molality of
chloroform must be used?