SCH 3U
Solubility Graphs
Define the following terms in your own words and provide an example for each;
Term
Solute
Definition
Example
Solvent
Solution
Unsaturated
solution
Saturated
solution
Super saturated
solution
Use the solubility curve graph provided to answer the following questions.
1. What are the customary units of solubility on solubility curves? ___________
2. Define solubility. __________________________________________________
3. According to the graph, the solubility of any substance changes as _________ changes.
4. List the substances whose solubility decreases as temperature increases. ___________
_______________________________________________________________
5. Which substance is least affected by temperature changes? ____________________
6. How many grams of ammonium chloride (NH4Cl) at 50°C? ______________________
7. _____________ and ____________ have the same solubility at approximately 78°C.
8. Which compound is least soluble in water at 10°C? ___________
9. How many grams of KNO3 can be dissolved at 50°C? __________
10. Are the following solutions unsaturated, saturated, or supersaturated?
a. 45g of NaNO3 in 100 g of water at 30°C.____________
b. 60g of KClO3 in 100 g of water at 60°C.____________
11. How many grams of sodium chloride, NaCl are required to saturate 100 grams of water at 100° C?
______
12. How many grams of NaNO3 are required to saturate 100 grams of water at 90°C?____
13. How many grams of KI will saturate water at 20°C?________
14. At what temperature would 25g of potassium chlorate (KClO3) dissolve? _______
15. At what temperature would 55g of NH4Cl dissolve? ________
16. 89 g NaNO3 is prepared at 30°C. a) Will all of the salt dissolve? ____________
b) What mass of NaNO3 will dissolve at this temperature? __________
17. If 25 grams of NH4Cl is dissolved at 50°C, how many additional grams NH4Cl would be needed to
make the solution saturated at 80°C? _________
18. At 50°C, how many grams of KNO3 will dissolve? _________
19. At 70°C, how many grams of cerium (III) sulfate (Ce2(SO4)3) dissolve? __________
20. Determine if each of the following is unsaturated, saturated, or supersaturated.
a. 55g of NH3 at 20°C
_________
f. 80g of NaNO3 at 10°C
_________
b. 10g of Ce2(SO4)3 at 10°C
_________
g. 145g of NaNO3 at 80°C _________
c. 125g of KNO3 at 60°C
_________
h. 35g of NaCl at 100°C
d. 65g of NH4Cl at 80°C
_________
e. 12g of NH3 at 90°C
_________
_________
Use the following solubility graph to answer the following questions.
1. What mass of potassium
chlorate can be dissolved in
100 mL at 70 °C?
__________________
2. What is the solubility of
ammonium chloride at 50
°C? ___________
3. From the graph, determine
the temperature of
potassium chlorate when its
solubility is:
20 g / 100 mL
______
50 g / 100 mL
______
4. At what temperature are the
solubilities of potassium
nitrate and potassium
chloride approximately
equal? _________
5. Determine the mass of
potassium nitrate that will
come out of solution when
the temperature is decreased
from 50 °C to 20 °C?
__________________
6. Write a general statement concerning the solubility of the ionic substances as the temperature
increases.
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
Creating Solubility Graphs
On the graph paper provided, plot graphs of solubility (dependent axis (y)) versus temperature for the
following chemicals. Orient your graph in landscape and use both the left side for ammonium chloride
and a new axis on the right for carbon dioxide, plot both curves on the same graph.
Ammonium Chloride
Solubility (g/L)
Temperature °C
300
0.0
372
20.0
458
40.0
550
60.0
658
80.0
771
100.0
Carbon dioxide
Solubility (g/L)
Temperature °C
3.4
0.0
1.8
20.0
1.2
40.0
0.86
60.0
Questions
1. From the graph, determine the solubility of ammonium chloride at:
i. 10°C _____
ii. 30 °C
_____
iii. 70 °C
_____
2. From the graph, determine the solubility of carbon dioxide at:
i. 10°C _____
ii. 30 °C
_____
iii. 50 °C
_____
3. From the graph, determine the temperature of ammonium chloride when the solubility is
i. 400 g/L _____
ii. 650 g/L
_____
4. From the graph, determine the temperature of carbon dioxide when the solubility is
i. 1.6 g/L _____
ii. 2.4 g/L
_____
5. Make a general statement concerning the solubility of each of the substances as the temperature
increases.
___________________________________________________________________
___________________________________________________________________
__________________________________________________________________
6. For each of the following temperature changes, determine the mass of ammonium chloride
that would have to be added to keep the solution saturated:
i. 0 °C to 20°C _____
ii. 40°C to 100°C
______
iii. 10°C to 50°C
_____
7. Determine the mass of carbon dioxide that will come out of solution, when the temperature is
increased in each of the following situations:
i. 0°C to 60°C _____
ii. 10°C to 50°C
_____
8. Determine the mass of ammonium chloride that will come out of solution when the
temperature is decreased from 100°C to 10°C. _____
Textbook work:
Read pgs. 312-316. Answer practice questions on ****pg. 316 # 1,2
SOLUBILITY CURVE WORKSHEET KEY
Use your solubility curve graphs provided to answer the following questions.
1. What are the customary units of solubility on solubility curves? Degress Celsius and grams of
solute/100g of water
2. Define solubility. A measure of how much solute can dissolve in a given amount of solvent.
3. According to the graph, the solubility of any substance changes as temperature changes.
4. List the substances whose solubility decreases as temperature increases. NH3 and Ce2(SO4)2
5. Which substance is least affected by temperature changes? NaCl,
6. How many grams of ammonium chloride (NH4Cl) at 50°C? 50g
7. NaCl and KClO3 have the same solubility at approximately 78oC.
8. Which compound is least soluble in water at 10°C? KClO3
9. How many grams of KNO3 can be dissolved at 50oC? 80g
10. Are the following solutions unsaturated, saturated, or supersaturated?
a. 45g of NaNO3 in 100 g of water at 30°C. saturated
b. 60g of KClO3 in 100 g of water at 90°C. supersaturated
11. How many grams of sodium chloride, NaCl are required to saturate 100 grams of water at 100° C?
40g
12. How many grams of NaNO3 are required to saturate 100 grams of water at 75°C? 140g
13. How many grams of KI will saturate water at 20°C? 33g
14. At what temperature would 25g of potassium chlorate (KClO 3) dissolve? 600C
15. At what temperature would 60g of NH4Cl dissolve? 700C
16. 89 g NaNO3 is prepared at 30°C.
a) Will all of the salt dissolve? No_
b) What mass of NaNO3 will dissolve at this temperature? 95g
17. If 50 grams of NH4Cl is dissolved at 50°C, how many additional grams NH4Cl would be needed to
make the solution saturated at 80°C? 15g
18. At 50°C, how many grams of KNO3 will dissolve? 80g
19. At 70°C, how many grams of cerium (III) sulfate (Ce2(SO4)3) dissolve? 5g
20. Determine if each of the following is unsaturated, saturated, or supersaturated.
a. 55g of NH3 at 20oC supersaturated f. 78g of NaNO3 at 10oC. saturated
b. 10g of Ce2(SO4)3 at 10oC unsaturated g. 145g of NaNO3 at 80oC. saturated
c. 110g of KNO3 at 60oC. supersaturated h. 35g of NaCl at 100oC. unsaturated
d. 65g of NH4Cl at 80oC. saturated
e. 12g of NH3 at 90oC. supersaturated