Deck 6: Solutions

Question 1

96.5 grams of an unknown substance were diluted with water in a 1.000 L volumetric flask. It was determined that the concentration of the substance was 1.22 M. What is the molar mass of the unknown substance?

A) 117 g·mol^-1
B) 79.1 g·mol^-1
C) 1.26´10^-2 g·mol^-1
D) 65.4 g·mol^-1

Answer 1

79.1 g·mol^-1

Question 2

Equal volumes of ethanol (C₂H₅OH) and water are mixed. If the density of water is 1.00 g·cm^-3 and that of ethanol is 0.789, what is the mole fraction of ethanol in the mixture?

A) 0.764
B) 0.309
C) 0.324
D) 0.236

Answer 2

0.236

Question 3

120.0 grams of calcium nitrate are weighed out and placed into a 1.5 L volumetric flask and the flask filled to the mark. What is the concentration of the nitrate ions in solution?

A) 0.9751
B) 0.4875
C) 1.026
D) 2.051

Answer 3

0.9751

Question 4

How many ml of 0.1506 M NaOH are required to reach the endpoint in a titration with 30.00 ml of 0.2215 M HCl?

A) 20.40
B) 30.15
C) 31.18
D) 44.12

Question 5

Which, if any, of the following would you expect to readily dissolve in water?

A)

B)

C)
D) a and c
E) none of the above

Question 6

What is the expected boiling point of a solution made by combining 400.0 g of water with 100.0 g of Na₂CO₃?

A) 103.6°C
B) 113.5°C
C) 101.2°C
D) 104.8°C

Question 7

The following question(s) pertain to the dissolution of 200.0 g of KMnO4 into 600.0 g. of water.

-Refer to Exhibit 11-2. What is the molality of the KMnO₄ in the 800.0 gram solution?

A) 1.255 m
B) 2.109 m
C) 1.054 m
D) 2.223 m

Question 8

The following question(s) pertain to the dissolution of 200.0 g of KMnO4 into 600.0 g. of water.

-Refer to Exhibit 11-2. What is the mole fraction of MnO₄^- ions in the solution?

A) 0.0353
B) 0.0365
C) 0.0433
D) 0.0333

Question 9

pertain to the dissolution of 200.0 g of KMnO4 into 600.0 g. of water.

- Refer to Exhibit 11-2. If 200.0 ml of a solution that was 0.20 M in KMnO4 were added to the 800.0 g solution, would you expect the boiling point of that solution to go up?

A) Yes
B) No
C) More data is needed to answer the question

Question 10

To prepare 0.250 L of a 0.115_M NaBr solution, a technician must mix

A) 0.115 moles of NaBr with 0.250 L of H₂O.
B) 0.115 moles of NaBr with 0.250 kg of H₂O.
C) 0.115 moles of NaBr with enough H₂O to produce 0.250 kg of solution.
D) 0.115 moles of NaBr with enough H₂O to produce 0.250 L of solution.
E) none of these

Question 11

320 mL of 1.00 M HCl(aq) is combined with 1.18 L of 0.125 M HCl(aq) to give a total volume of 1.50 L. The molarity of the HCl in the final solution is

A) 0.562 M
B) 0.468 M
C) 0.312 M
D) 0.175 M
E) none of these

Question 12

Acetone (mw = 58.08, P 25°C =232 mmHg) and butanone (mw = 72.11, P 25 °C =100 mmHg) have the indicated molar masses and vapor pressures. A container holds 1.00 kg of butanone. How much acetone must be added to the butanone to elevate the total vapor pressure over the mixture to 125 mmHg at 25°C?

A) 5.313 kg
B) 290 g
C) 188 g
D) More information needed
E) None of the above