Self assessment: Solubility and Concentration
1. ____________________ How many grams of
NaClO3 are needed to make a saturated
solution in 100 g of water at 30 °C?
2. ____________________ In terms of
saturation, how would you classify a KBr
solution with a concentration of 90 g /
100 g of water at 110 °C?
3. ____________________ At what temperature
is the solubility of KBr the same as that
of KNO3?
4. ____________________ Which is more
soluble in water, NaCl or KBr? How can
you tell?
5. Are any of the substances gases? Explain.
How do the following affect the process of dissolving, at a molecular level?
6. Stirring/shaking?
7. Breaking it into smaller pieces?
8. Heating the solvent?
9. Why is water a polar molecule?
10. Describe how/why Like Dissolves Like.
Concentration = g (solute)/ ml (solvent)
11. ____________________ What is the concentration of 42.1 grams of silver nitrate that
dissolves in 1750 mL of water?
12. ____________________ How many grams of salt will dissolve in 350 mL of water is
the solubility of salt is 35.9 g / 100. mL of H2O?
13. ____________________ I want a solution with a concentration of 180 g / mL. If I
only have 400. g of solute, how many mL can I make?
Self assessment: Solubility and Concentration
112g
1. _____
_______ How many grams of
NaClO3 are needed to make a
saturated solution in 100 g of water
at 30 °C?
unsaturated_ In terms of
2. __
saturation, how would you classify a
KBr solution with a concentration of
90 g / 100 g of water at 110 °C?
(It’s holding less
than the maximum it
can….)
50 C
o
3. ____
________ At what temperature is the solubility of KBr the same as
that of KNO3?
KBr_______ Which is more soluble in water, NaClO3 or KBr? How can you
4. _____
tell?
You can dissolve more at all temperatures, so it
is more soluble (tell me more than “the line is
higher”…tell me what that means when the line
is higher!)
5. Are any of the substances gases? Explain.
No. If they were, the line would go down as
temp. goes up.
How do the following affect the process of dissolving, at a molecular level?
6. Stirring/shaking?
Moves molecules away, so more room for
interactions with solute.
7. Breaking it into smaller pieces?
More surface area for interactions
between water and solute molecules.
8. Heating the solvent?
Molecules of solute and solvent move
faster and interact more
9. Why is water a polar molecule?
Uneven distribution of electrons…one
side has a little positive charge (+) and one
side is a little negative (-)
10. Describe how/why Like Dissolves Like.
Polar things will dissolve in polar
solvents, nonpolar solutes will dissolve in
nonpolar solvents. Because the charges in a
polar molecule will pull apart the other if it also
has charges. (polar will pull apart polar, but not
nonpolar)
Concentration = g (solute)/ ml (solvent)
.024 g/mL___ What is the concentration of 42.1 grams of silver
11. __
nitrate that dissolves in 1750 mL of water?
42.1 g
1750 mL
x = .0240571
130 g___ How many grams of salt will dissolve in 350 mL of water is
12. ___
the solubility of salt is 35.9 g / 100. mL of H2O?
35.9 g
100mL
=
35.9 x 350 = 100 x
x = 125.65
xg
350mL
12565 = 100 x
2.2 mL__ I want a solution with a concentration of 180 g / mL. If I
13. __
only have 400. g of solute, how many mL can I make?
180 = 400/x
180x = 400
x = 400/180
x = 2.22222222