Name: ___________________________________ Period: _____ Date: ____________________
Solubility and Concentration Pretest
1. – 2. I mix up a solution of some Kool Aid by using the mix, sugar and water. What
is the solute and what is the solvent?
3. – 5. Define these terms:
Saturated:
Unsaturated:
Supersaturated:
6. I add some more sugar to the Kool Aid from 1. – 2. and it dissolves. Which of the
above three terms best describes the solution? Explain.
7. ____________________ How many grams of
KBr are needed to make a saturated
solution in 100 g of water at 30 °C?
8. ____________________ In terms of
saturation, how would you classify a
KBr solution with a concentration of
90 g / 100 g of water at 50 °C?
9. ____________________ If we raised the
temperature to 100 °C, what would its
saturation be?
10. ____________________ At what
temperature is the solubility of KBr
the same as that of KNO3?
11. ____________________ Which is more
soluble in water, NaClO3 or KBr? How can you tell?
12. – 13. As you raise the temperature of a solvent, how does the solubility of a
solute change if it is a
Solid or liquid? Explain why.
Gas? Explain why.
14. Are any of the substances gases? Explain.
How do the following affect the process of dissolving, at a molecular level?
15. Stirring/shaking?
16. Breaking it into smaller pieces?
17. Heating the solvent?
18. Why is water a polar molecule?
19. Describe how/why “like dissolves like.”
20. ____________________ What is the concentration of 42.1 grams of silver nitrate that
dissolves in 1750 mL of water?
21. ____________________ How many grams of salt will dissolve in 350 mL of water is
the solubility of salt is 359 g / 100 mL of H2O?
22. ____________________ If the solubility of KNO3 is 180 g / 100 mL of H2O, will 560 g
dissolve in 400 mL of H2O?
Name: ___________________________________ Period: _____ Date: ____________________
Solubility and Concentration Pretest
1. – 2. I mix up a solution of some Kool Aid by using the mix, sugar and water. What
is the solute and what is the solvent?
Solute: Kool Aid, sugar (what gets mixed)
Solvent: water (what it’s mixed into)
3. – 5. Define these terms:
solvent holds as much solute as it can
at that temperature
Saturated:
solvent holds less than the
maxiumum solute it can at that
temperature
Unsaturated:
solvent holds more than the
maxiumum solute it can at that
temperature
Supersaturated:
6. I add some more sugar to the Kool Aid from 1. – 2. And it dissolves. Which of the
above three terms best describes the solution? Explain.
Unsaturated…it was holding less so it
dissolved. If it was saturated or
supersaturated, it would fall to the
bottom and not
dissolve.
~ 72 g__ How many grams of
7. __
KBr are needed to make a saturated
solution in 100 g of water at 30 °C?
supersaturated_ In terms of
8. _
saturation, how would you classify a
KBr solution with a concentration of
90 g / 100 g of water at 50 °C?
unsaturated_ If we raised the temperature to 100 °C, what would its
9. _
saturation be?
~ 48 oC _ At what temperature is the solubility of KBr the same as that of
10. _
KNO3?
11. __
NaClO3_ Which is more soluble in water, NaClO3 or KBr? How can you
tell?
The line on the graph is higher, which
means more can dissolve
12. – 13. As you raise the temperature of a solvent, how does the solubility of a
solute change if it is a
Solid or liquid? Explain why.
Increases.
As the molecules of both move faster,
more solute can dissolve
Gas? Explain why.
Decreases.
As the molecules of both move faster,
more solute escapes the solvent
14. Are any of the substances gases? Explain.
No.
All increase solubility with temperature.
How do the following affect the process of dissolving, at a molecular level?
15. Stirring/shaking?
Moves around, more interactions
between molecules
16. Breaking it into smaller pieces?
Increases surface area for interactions to
take place
17. Heating the solvent?
Moves molecules faster  more
interactions
18. Why is water a polar molecule?
Shares electrons unevenly
Has partial charges
19. Describe how/why “like dissolves like.”
Partial charges in polar molecules help pull
apart the partial charges from other
polar molecules.
.0241 g/ml_ What is the concentration of 42.1 grams of silver nitrate
20. _
that dissolves in 1750 mL of water?
42.1 / 1750 = .024057142
1000 g_ How many grams of salt will dissolve in 350 mL of water is
21. _
359
100
the solubility of salt is 359 g / 100 mL of H2O?
=
x
350
1256.5
yes_ If the solubility of KNO3 is 180 g / 100 mL of H2O, will 560 g dissolve in
22. _
400 mL of H2O?
That concentration is less than its solubility
560/400 = 1.4 g/ml
180/100 = 1.8 g/ml