CHM 2046C Sample Exam Answers
Module Eight Part II: Solutions Chapter 14
Part Q: Factors
Affecting Solubility 4 point
1) Describe the two external factors which affect the solubility of
gases in liquids,
then compare the same factors with solubility
of solids in liquids.
Pressure and temperature are two external factors that
influence the solubility. Both affect the solubility of gases in liquids, where
as only temperature is an important factor in the solubility of solids in
liquids.
The solubility of a gas is directly proportional to the gas
pressure, while solubility of a gas in a liquid increases with a decrease in
temperature.
However, solubility of solids in liquids usually increases with an increase in Temperature, but there are notable exceptions
2) State Henry’s Law and give its
formula. Explain or label each term:
The solubility of a gas is a liquid is directly proportional
to the gas pressure.
Sg = kHPg
Where: Sg is the gas solubility;
Pg
is the partial pressure of the gaseous solute;
kH is the Henry’s Law
constant
3) State Le Chatelier’s
Principle as it describes how temperature affects
Solubility?
La Chatelier’s Principle: A change
in any of the factors determining the equilibrium causes the system to adjust
so as to reduce or counteract the effect of the change.
If you heat a solution of a gas in a liquid, the equilibrium
will shift left feeing gas molecules to the environment, decreasing the
solubility.
If you heat a solution you can dissolve more sugar in water,
but if you heat water there will be little effect on the solubility of Table
salt in water.
Similar Problems: Kotz Chapter 14 p693 p13-20