Name _______________
Chemistry
Period ___
Date ________________
SOLUTIONS WORKSHEET
A. Solubility curves – refer to the graph to answer the following questions.
1. What is the solubility of NH4Cl at 70oC? 60 g
2. Calculate the mass of NH4Cl that would dissolve in 200 g
of water at 90oC.
70 g @ 100g water  140 g
3. At 0oC, 50.0 g NH4Cl are added to 100 g water. To what
temperature does the solution have to be raised in order
to achieve a saturated solution of NH4Cl(aq)?
50oC
4. Is NH3 a (s), (l), or (g)? Explain.
GAS – it’s solubility decreases with increase in temperature. Opposite for solids
5. Determine how much water is required to dissolve 35.0 g NH4Cl at 70oC in order to make
a saturated solution. Show your work.
60 = 35
100 x
x = 58.3 g H2O
6. If a saturated solution of NH3 at 15oC is warmed to 40oC, how much ammonia will “fall
out” of the solution?
@ 15oC – 60 g soluble
@ 40oC – 35 g soluble
25 g will fall out
B. MOLARITY
1. What is molarity a measure of? What is the formula for molarity? What are the units of
molarity?
Concentration.
M=n/V
mol/L or M
2. Calculate the molarity of a 1.5 L solution that has 0.45 mol solute dissolved.
0.30 - M
3. Calculate the grams of sodium sulfate that are required to prepare 1.50 L of 0.25 M
solution.
53.3 g Na2SO4
4. Calculate the volume of solution required to make 0.024 M solution using 15.0 g of
calcium chloride.
V = 5.6 L
5. Describe in detail the steps you would take to prepare 1.50 L of 0.5 M solution of sodium
chloride.
n = 0.75 mol  43.5 g NaCl
1) measure out 43.5 g NaCl
2) put NaCl into graduated cylinder
3) add enough water to make final volume 1.50 L
C. DILUTION
1. Define dilute and concentrated.
Dilute – little solute compared to a lot of solvent
Concentrated - a lot of solute compared to little solvent
2. Calculate the volume of 12 M HCl(aq) needed to make 300 ml of 1.5 M HCl(aq).
V = 37.5 ml
3. Calculate the new molarity that results when 25.2 ml of 15 M HNO3 is diluted to a final
volume of 1.0 L.
M = 0.378 M
D. MOLALITY & FREEZING POINT DEPRESSION
1. What is molality a measure of? What is the formula for molality? What are the units of
molality?
Moles of solute per kilogram of solvent. m = n/m
mol/kg or m
2. Calculate the molality of a solution made from 0.50 g CO2 in 652 g water.
0.017 m
3. Calculate the mass of glucose needed to make a 0.238 m solution in 1000 g water.
43 g C6H12O6
4. What is meant by freezing point depression? What is the formula?
The freezing point of a solution is lower than the pure solvent
(formula not needed for test)
5. Determine the temperature at which the following solution will freeze:
50.0 g sucrose (C12H22O11) in 200 g water
m = 0.73 mol/kg
T = -1.36oC
6. Determine the temperature at which the following solution will freeze:
0.328 mol naphthalene in 250 g benzene
m = 1.312 mol/kg
SOLVENT
benzene
water
T = -0.93oC
FREEZING POINT (oC)
5.5
0.0
kf
4.90
1.86