Unique Designation:_______________
Solutions Test
1) Which of the following represents the correct solubility constant for the reaction:
CaCl2 + H2O à Ca+ + 2Cl-
(A) [Ca+] [Cl-]2 (B) [Ca+] [Cl-] (C) [Ca+] [Cl-]2 (D) [CaCl2]
[CaCl2] [Ca+] [Cl-]2
2) Which expression represents the molarity (M) of a solution?
(A) moles of solvent (B) moles of solvent (C) moles of solute (D) moles of solute
1000g of solution 1000ml of solution 1000g of solution 1000ml of solution
3) What happens when KI(s) is dissolved in water?
(A) I- ions are attracted to the oxygen atoms of the water.
(B) K+ ions are attracted to the oxygen atoms of the water.
(C) K+ ions are attracted to the hydrogen atoms in the water.
(D) No attractions are involved; the crystal just falls apart.
4) What is the % by mass of a solution in which 60.0g of NaOH are dissolved in sufficient water to make 100g of solution?
(A) 16% (B) 40% (C) 60% (D) 160%
5) The Depression of the freezing point is dependent on?
(A) The nature of the solute
(B) The formula mass of the solute
(C) The concentration of the dissolved particles
(D) The hydrogen bonding
6) Which salt has the greatest change in solubility between 30 degrees C and 50 degrees C?
(A) KNO3 (B) KCl (C) NaNO3 (4) NaCl
7) Under which conditions are gases most soluble in water?
(A) High temperature and high pressure
(B) High temperature and low pressure
(C) Low temperature and high pressure
(D) Low temperature and Low pressure
8) What is the percent by mass of a solution if 60.g of acetic acid are added to 90g of water? (A) 20% (B) 30% (C) 40% (D) 67%
9) If a 1.0M solution is evaporated to a volume of 25ml, what will be the concentration of the resulting solution? (A) 0.25M (B) 0.50M (C) 2.0M (D) 4.0M
10) A solution contains 14g of KCl in 100g of water at 40 degrees C. What is the minimum amount of KCl that must be added to make this a saturated solution?
(A) 19g (B) 14g (C) 25g (D) 44g
11) Which of the following substances is least soluble in 100g of water at 50 degrees C?
(A) NaCl (B) KCl (C) NH4Cl (D) HCl
12) What is the total number of moles of the solute H2SO4 needed to prepare 5.0L of a 2.0M solution of H2SO4?
(A) 2.5 mol (B) 5.0 mol (C) 10. mol (D) 20. mol
13) The diagrams below represent an ionic crystal being dissolved in water.
According to the diagrams, the dissolving process takes place by
(A) hydrogen bond formation
(B) Metallic bonding
(C) Dipole-dipole attractions
(D) Molecule-ion attractions
14) What is the molarity of a solution that contains 40.g of NaOH in .50 L of solution? (A) 1.oM (B) 2.0M (C) .50M (D) .25M
15) A substance has a solubility of 350 ppm. How many grams of the substance are present in 1.0L of a saturated solution?
(A) 0.0350g (B) .350g (C) 3.50g (D) 35.0g
16) What is the molarity of an H2SO4 solution if .25L of the solution contains .75 mol of H2SO4? (A) .33M (B) .75M (C) 3.0M (D) 6.0M
17) Carbon dioxide gas has a solubility of .0972g/100g H2O at 40 degrees C. Expressed in ppm, this concentration is closest to
(A) .972ppm (B) 9.72 ppm (C) 97.2ppm (D) 972 ppm
18) In a true solution the dissolved particles
(A) are visible to the eye
(B) will settle out on standing
(C) are always solids
(D) cannot be removed by filtration
19) When a teaspoon of sugar is added to water and stirred, the sugar
(A) melts (B) dissolves (C) condenses (D) evaporates
20) In aqueous solution of potassium chloride the solute is
(A) Cl- only (B) K+ only (C) K+ Cl- (D) water
21) Compared to pure water, an aqueous solution of calcium chloride has a
(A) higher boiling point and higher freezing point
(B) higher boiling point and lower freezing point
(C) lower boiling point and higher freezing point
(D) lower boiling point and lower freezing point
22) Which of these terms refers to matter that could be heterogenous?
(A) element (B) mixture (C) compound (D) solution
23) According to your reference tables, which of these salts is least soluble in water?
(A) LiCl (B) RbCl (C) FeCl2 (D) PbCl2
24) At standard pressure when NaCl is added to water, the solution will have a
(A) higher freezing point and a lower boiling point than water
(B) higher freezing point and a higher boiling point than water
(C) lower freezing point and a higher boiling point than water
(D) lower freezing point and a lower boiling point than water
25) As the temperature rises, the solubility of all gases in water
(A) decreases (B) increases (C) remains the same (D) depends on the gas
Application
Show all work to get partial credit
26) Describe Two methods by which you could remove gases that are dissolved in water?
27) Describe how to prepare 500ml of 4.0M NaOH(aq).
______________________________________________________________________
A student uses 200g of water at a temperature of 60 degrees C to prepare a saturated solution of KCl.
28) Identify the solute in this solution
29) According to the reference tables, how many grams of KCl must be used to create a saturated solution?
30) This solution is cooled to 10 degrees C and the excess KCl precipitates. The resulting solution is saturated at 10 degrees C. How many grams of KCl precipitated out of the original solution?
31) At what temperature do KClO3 and KCl have the same solubility in water?
32) Among the components of typical urban smog is NO2. If air has an average density of 1.29 grams per liter, and NO2 is reported at .20 ppm, what mass of NO2 is found in 1.0 liter of air?
33) Dioxin, one of the most hazardous synthetic substances, is reported to be present in well water near a dump site at the concentration of .07 parts per million. If an individual takes in 3 liters of water per day, what mass of dioxin will be taken in per month? (30 days)
34) A solution of sucrose has a density of 1.20 g/ml. It is 45.0% by mass sucrose. What volume of solution contains 100 grams of sucrose?
35) What mass of ethanol, C2 H5 OH, must be dissolved in 825g H2O to prepare a solution which is 35% ethanol by mass?
36) If the solubility product of a dissociation equation is low, what is true of the concentration of the ions in solution?
37) Would CaCl2 or NaSO4 produce more of a boiling point elevation in solution?
38) Provide a dissociation equation for both the compounds in the previous question.
39) Is the Ksp of AgCl low or high?
40a) Why do ionic formulas like CaCl2 provide more of a freezing point depression than covalent ones like sugar?
40b) What does this suggest about covalent compounds in water?
41) Sports drinks like Gatorade all claim to have electrolytes. Why is this important for you? (hint: your body uses electrical impulses to send nerve transmission)
42) Why is it important to replenish your electrolytes when working out? (hint: think of your skin as a type of filter.)
43) In the winter, salt is put on the sidewalks to keep them from freezing up. It is not NaCl that is used however. Most often CaCl2 is used to keep the sidewalks and roads ice free. Name a reason that CaCl2 is preferable to NaCl.
44) Another salt that would be better than NaCl is NaNO3. Why would NaNO3 be better than NaCl? (hint: look at table G in your tables)
45) Soda companies all package their products under very high pressures. If they wanted to package them under less pressure what steps would they have to take to get the same amount of gas in solution?
46) The boiling point of a solution is raised when there are ions in the solution. What can you infer then, about the effect of a solute on the vapor pressure of a solvent?
47) A sample of ground water contains 15 ppm Mg2+ ions. How many Mg2+ ions are there in 1.00kg of this ground water?
48) What molarity is the ground water in the above question?
49) Why does a solute lower the vapor pressure in a solvent?
E.C.) Another unit of measure that is often used is % volume. If a mixture is 40% ethanol to water by volume, and the density of ethanol is 0.789g/ml, what is the % by mass?