Unit 12 Problems 1
Name ______ KEY___________________________________ Date _________ Period ______
Unit 12: Thermodynamics and Solutions Notes Problems

Henry’s Law
1.
The solubility of a gas in water is 0.16 g/L at 104 kPa. What is the solubility when
the pressure of the gas is increased to 288 kPa? Assume the temperature remains
constant.
L

Solubility Curves
2.
Which solute has the highest solubility at 10 °C?

3.
Which is least soluble at 10 °C?

4.
Ce2(SO4)3
Which solubility changes the least
from 0-100 °C?

6.
KClO3
Which solute becomes less soluble as
temperature goes up?

5.
NaNO3
NaCl
What type of solution will be formed if
30 g of KCl are added at 40 °C?

Unsaturated
7.
How many grams of KClO3 can
dissolve in 200 g of water at 70 °C?
8.
What is the solubility of K2Cr2O7 at:
a. 50 °C?

30 g
b. At 20 °C?

10 g
Unit 12 Problems 2
9.
If you have a saturated solution of K2Cr2O7 at 50 °C, how much will precipitate at
20 °C?
30 g – 10 g = 20 g

Concentration
10.
Convert 225 mL to L.
L
11.
What is the molarity of a solution with 2.0 moles of NaCl in 0.25 L of solution?
12.
What is the volume of a 0.786 M solution if it contains 0.255 moles of BaS?
L
13.
How many grams of CuF2 are needed to make 250 mL of a 3.0 M solution?
mol = MV = (3.0 M)(0.25 L) = 0.75 mol;
14.
How much concentrated 12.0 M hydrochloric acid is needed to prepare 100. mL
of a 2.00 M solution?
(
15.
)
L
What is the concentration if 3.50 L of solution are made from 0.750 L of a 6.50 M
solution?
(
)
16.
If 3.56 mol of Ca(OH)2 is dissolved in 1.35 kg of water, what is the molality of
the solution?
17.
How many moles of KCl are needed to make a 1.21 m solution with 750. g of
H2O?
mol = (m)(kg) = (1.21 m)(0.750 kg) = 0.908 mol
Unit 12 Problems 3
18.
A 0.50 m solution is made by dissolving 99.8 g of FeP. How much solvent must
be added?
19.
If 35.7 g of Pb(NO3)3 are dissolved in 451 g of solution, what is its mass percent?
20.
If 67.1g of CaCl2 is added to 275 g of water, calculate the mass percent of CaCl2
in the solution.
21.
What mass of Ba3N2 is found in 76.9 g of a 15.0 % by mass solution?
a

Specific Heat
22.
Aluminum has a specific heat of 0.897J/g°C. How many joules are absorbed by
’
p r r r
r
°
° ?
q
23.
ΔT
45.2 g)(0.897 J/g°C)(76.8 °C – 12.5 °C) = 2610 J
A cup of hot water cools from 74.6 °C to 22.4 °C. If 49,100 J are lost, what is the
mass of the water? (c = 4.184 J/g°C)
q
T
24.
°
°
°
Copper has a specific heat of 0.385 J/goC. Find the final temperature if 565.2 J are
added to 115 g of copper at 22.4 oC.
T
Tf
°
°
ΔT + Ti = 12.8 °C + 22.4 °C = 35.2 °C