PreAP Chemistry Solutions Review
1. Vocabulary: Define in your own words
dissociation process of separating solute particles into their component ions
electrolyte solution that conducts electricity
solvation surrounding of solute particles by solvent
hydration surrounding of solute particles by water molecules
miscibility two liquids that are mutually soluble are miscible
supersaturated a solution that contains more solute particles than normal for the temperature and
amount of solvent
saturated a solution that contains the expected amount solute particles for the temperature and amount
of solvent
unsaturated a solution that contains less solute particles than normal for the temperature and amount of
solvent
Brownian motion particle movement by rapid jumps in random direction
colligative properties properties of solutions that depend on the ratio of solute particles to solvent
molecules
dilute a solution containing a relatively small number of solute particles to amount of solvent
concentrated a solution containing a relatively large number of solute particles to amount of solvent
solution a homogenous mixture
solute the substance which is dissolved in the solvent during the dissolution process
sovent the substance that dissolves the solute to form the solution
heat of solution the amount of heat energy released or absorbed during the dissolution process
enthalpy the energy released or absorbed during a chemical reaction
entropy the state of disorder of a system
exothermic a process in which energy is released
endothermic a process in which energy is absorbed
molarity a measurement of concentration comparing moles of solute to liters of solution
molality a measurement of concentration comparing moles of solute to kilograms of solvent
mole fractiona measurement of concentration comparing moles of solute to total moles of solution
mass percent a measurement of concentration comparing mass of solute to total mass
concentration amount of solute in solution
tyndall effect light scattering by particles in a colloid or suspension
volatile describes a substance that is easily vaporized at a low temperature
Concept Thoughts:
2.
Which would be most likely to dissolve in water to form an electrolyte?
sugar
calcium phosphate
ethanol (C2H5OH)
sodium nitrate
3.
The solubility of which of the following solutions would be most affected by a change in vapor pressure?
sodium chloride dissolved in water
ethanol dissolved in water
carbon dioxide dissolved in water
ethanol dissolved in carbon tetrachloride
Which of the following sets correctly go together?
exothermic dissolution, positive heat of solution, negative sloping solubility curve
endothermic dissolution, positive heat of solution, negative sloping solubility curve
endothermic dissolution, positive heat of solution, positive sloping solubility curve
exothermic dissolution, negative heat of solution, positive sloping solubility curve
PreAP Chemistry Solutions Review
4.
Which of the following pairs match?
most solid/liquid solutions, endothermic dissolution
most solid/liquid solutions, negative sloping solubility curve
most gas/liquid solutions, negative heat of solution
most gas/liquid solutions, positive sloping solubility curve
5.
Raoult’s law deals with the relationship between mole fraction of the solution and which of the following?
type of solvent
vapor pressure
polarity
amount of solute
6.
When a solute is added to a solvent, which of the following is true?
the boiling point of the solute is raised
the freezing point of the solute is raised
the boiling point of the solvent is lowered
the freezing point of the solvent is lowered
7. Which salt(s) will be more soluble at higher temperatures?
NaNO3, KNO3, KI, NH4Cl, KCl, NaCl, KClO3
8. Which salt will be affected the most by a change in
temperature? KNO3
9. Which salt(s) will be saturated at 73 C with 135 g of solute
in 100 g of water? NaNO3 and KNO3
10. Which salt will have the greatest effect on the boiling point
of the water in the solution?
Ce2(SO4)3
11. Which compound(s) have negative heats of solution?
NH3 and Ce2(SO4)3
Problems:
12. What would be the molarity of 3.75 L of a solution containing 112.6g of calcium chloride?
112.6g CaCl2/1 mol CaCl2
= 0.271 M
3.75 L / 110.98 g CaCl2
13. How many grams of barium nitrate would need to be dissolved in 4.16 L of solution to produce a 1.12M
solution? 4.16L /1.12 mol Ba(NO3)2/261.35 Ba(NO3)2 = 1220 g Ba(NO3)2
1 /
1L
/ 1 mol Ba(NO3)2
14. If it takes 72.4g of a solute create 3.4 m solution in 754.4g of water, what is the molecular mass of the
solute? 28.23 g/mol
15. If you dissolve 43.2 g of sodium hydroxide in 125 g of water, how many milliliters of this solution would
you need to make 245 ml of a 0.112 m solution? 43.2 g NaOH/ 1 mol NaOH = 4.41 m
.245 kg H2O / 40.01 g NaOH
(4.41m)(V) = (0.112m)(245ml) = 6.22 ml
What would be the freezing point of a solution if 66.4 g of calcium nitrate were added to 556.3 g of
water? 66.4g Ca(NO3)2/ 1 mol Ca(NO3)2 = 0.728 m Newfp = Normfp – (m * Kfp * particles of solute)
.556.3kg H2O / 164.1g Ca(NO3)2
FP = 0 – (0.778 m * 1.86 Cm * 3)
FP = -4.34 C
PreAP Chemistry Solutions Review
16. If the boiling point of a solution containing 38.92 g of silver nitrate is 103.6 C, what mass of water is in
the solution? 103.6C = 100 C + (m * 0.512 Cm * 2) m = 3.52
38.92 g AgNO3/ 1 mol AgNO3/1 kg H2O
= 0.065 kg H2O
1
/169.88 AgNO3/ 3.52 mol AgNO2
17. What would be the vapor pressure of a solution of ethanol in benzene with a mole fraction of 0.421, if the
normal vapor pressure of benzene is .1252 atm. VPsoln = (0.421)(0.1252 atm)
VPsoln = 0.0527 atm
18. What would be the concentration in the following units, of a 2.36L sample of a solution that contains
16.87g of potassium chlorate in 2.349 kg of water:
M = 0.0584 M
m = 0.0586 m
mole fraction = 0.0016
mass percent = 0.713%
Complete the following reactions, and show the total ionic and net ionic forms of the equation:
BeI2 (aq) + Cu2SO4 (aq)
BeI2 (aq) + Cu2SO4 (aq)  BeSO4(s) + 2CuI(aq)
Be2+ + 2I- + 2Cu+ + SO42- BeSO4(s) + 2Cu+ + 2IBe2+ + SO42-  BeSO4(s)
rubidium fluoride + copper(II) sulfate
RbF(aq) + CuSO4(s)  Rb2SO4(aq) + CuF(aq)
Rb+ + F- + CuSO4(s)  2Rb2+ + SO42- + Cu+ + FCuSO4(s)  Cu+ + SO42barium nitrate + ammonium phosphate
3Ba(NO3)2(aq) + 2(NH4)3PO4(aq)  Ba3(PO4)2(s) + 6NH4NO3(aq)
3Ba2+ + 6NO3- + 6NH4+ + 2PO43-  Ba3(PO4)2(s) + 6NH4+ + 6NO33Ba2+ + 2PO43-  Ba3(PO4)2(s)