SOLUBILITY CURVES / HOMEWORK
I.
SOLUBILITY:
II.
III.
A. Saturated:
A solution containing the maximum amount of solute for a given amount of
solvent at a constant temperature and pressure.
B. Unsaturated:
A solution containing an amount of solute less than the maximum for a given
amount of solvent at a constant temperature and pressure.
C. Supersaturated:
A solution containing an amount of solute less than the maximum for a given
amount of solvent at a constant temperature and pressure.
Use the solubility curve below to answer the questions following it:
1.
How many grams of potassium nitrate can
be dissolved in 100 mL of water at 60
degrees Celsius? 102 g.
2.
how many grams of potassium nitrate will
saturate 100 mL of water at 10 degrees
Celsius? 22 g.
3.
How many grams of potassium nitrate will
precipitate (fall out of solution) if 100 mL of
a saturated solution of potassium nitrate at
60 degrees Celsius is cooled to 10 degrees
Celsius? 80 g.
4.
100 mL of water at 50 degrees Celsius can
hold 50 grams of ammonium chloride.
5.
100 mL of water at 80 degrees Celsius can
hold 40 grams of potassium chlorate.
6.
How many grams of sodium nitrate will
precipitate out of a 100-mL solution of
sodium nitrate if the solution is cooled from
80 degrees Celsius to 50 degrees Celsius?
10 g.
7.
If 50 grams of potassium chloride are
dissolved in 100 mL of water at 55 degrees
Celsius, will the solution be saturated,
supersaturated, or unsaturated? Super!
The following data describes the solubility of the gas, ammonia. Graph the data on the back and
connect the points. Then answer the questions that follow the graph.
Solubility (grams / 100-mL water)
Temperature (degrees Celsius)
65
10
50
20
35
40
25
50
20
60
10
80
8
100
40
30
20
10
Grams solute / 100 mL water
50
60
70
Graph:
10
1.
20
30
40
50
60
70
80
90
100
What phase is ammonia in? How do you know?
Ammonia is a gas because solubility is decreasing with increasing temperature.
2.
Will 40 grams of ammonia dissolve in 100 mL of water at 30 degrees Celsius?
No.
3.
Is the solution in #2 saturated, unsaturated, or supersaturated?
If 40 g. of ammonia is dissolved in 100mL of water at 20 degrees Celsius, then the solution is supersaturated.