Chem 106 Comp Exam 3 PRACTICE

1.

 

Two liquids that are insoluble in each other are considered

 

immiscible

 

miscible

 

unsaturated

 

isotonic

 

2.

 

Which of the following statements relating to a solution is NOT correct?

 

A solution may contain more than one solute.

 

A solution may contain only one solute.

 

Water is always the solvent in a solution.

 

More than one correct response is given.

 

3.

 

What is the molarity of a solution containing 0.612 moles of solute in 250 mL of solution?

 

2.45 x 10-3

 

0.408

 

2.45

 

408

 

4.

 

Calculate the molar concentration of a solution made by dissolving 8.60 grams of KCl in enough water to give 100 mL of solution.

 

0.860 M

 

1.15 M

 

0.115 M

 

5.45 M

 

5.

 

A solution is made by dissolving 300 mL of oil in enough gasoline to give 9.00 L of solution. What is the % (v/v) of oil in the solution?

 

333%

 

33.3 %

 

3.33 %

 

0.333%

 

6.

 

What is the volume of ethyl alcohol contained in 35 mL (1 oz) of 86 proof liquor, which is 43% (v/v) alcohol?

 

30 mL

 

43 mL

 

15 mL

 

37 mL

 

7.

 

Calculate the number of moles of BaCl2 in 200 mL of 0.625 M solution.

 

3.13

 

1.92

 

0.819

 

0.125

 

8.

 

An ethylene glycol and water solution does not conduct electricity. In water, ethylene glycol would be found as

 

ethylene glycol molecules

 

ethylene glycolate ions

 

ethylene ions and glycolate ions

 

no correct response

 

9.

 

Which of the following is NOT a colligative property?

 

boiling point changes

 

Tyndall effect

 

osmotic pressure

 

no correct response

 

10.

 

Which of the following would exhibit the highest vapor pressure at 25oC?

 

pure water

 

a 5% saltwater solution

 

a 10% saltwater solution

 

they would all have the same vapor pressure

 

11.

 

The dispersed phase of a colloid can be a

 

gas

 

liquid

 

solid

 

more than one choice is correct

 

12.

 

To keep particles in some colloids from coalescing, you would use a(n)

 

anticoagulant

 

dispersing medium

 

emulsifying agent

 

solvent

 

13.

 

Ice has an entropy ________ that of liquid water.

 

lower than

 

equal to

 

higher than

 

cannot tell

 

14.

 

A process that gains or accepts energy as it takes place is a(n)

 

exergonic process

 

spontaneous process

 

endergonic process

 

all of these

 

15.

 

An explanation of how a molecule changes shape as a reaction proceeds would be called a(n)

 

endergonic reaction

 

reaction mechanism

 

reaction rate

 

activation energy

 

16.

 

A reaction that has a large activation energy is

 

likely to occur if the reaction is exothermic

 

likely to occur if the reaction is endothermic

 

unlikely to occur

 

more than one choice is correct

 

17.

 

In a coal-fired power plant, the coal is pulverized into a powder prior to combustion to increase the combustion rate. By doing this, the ________ is changed

 

concentration of the reactants

 

temperature of the reactants

 

nature of the reactants

 

activation energy

 

18.

 

A + B = C

The reaction above occurs in a water solution. As time goes along, “A” and “B” are used up to produce “C”, which is insoluble in water and settles to the bottom of the container. As time goes along, the reaction rate will

 

increase

 

decrease

 

remain the same

 

19.

 

A reaction is endothermic, but proceeds very slowly. A catalyst is added to increase the reaction rate. After adding the catalyst, the reaction will be

 

endothermic

 

exothermic

 

cannot be determined with the information given

 

20.

 

A + B = C

When the reaction above is at equilibrium

 

new molecules of “A” are being formed

 

new molecules of “C” are being formed

 

both choices are correct

 

none of the above is correct

 

21.

 

An equilibrium exists where there are more products present than reactants. This equilibrium is said to

 

have a position to the right

 

have a position to the left

 

be stressed

 

be in a state of transition

 

22.

 

A + B = C + D

The reaction above is at equilibrium. What will happen if some “D” is added to the reaction vessel?

 

the concentration of “C” will increase

 

the concentration of “B” will decrease

 

the concentration of “A” and “B” will remain the same

 

the concentration of “A” will increase

 

 

23.

 

An equilibrium is established in the reaction above. What change would be observed in the appearance of the equilibrium mixture if a catalyst was added?

 

no change would be seen

 

the violet color of the mixture would become lighter

 

the violet color of the mixture would become darker

 

no correct response

 

24.

 

2HBr = H2 + Br2

What will happen to the equilibrium above if H2 is added to the reaction vessel?

 

no change will occur

 

the equilibrium will shift right

 

the equilibrium will shift left

 

25.

 

Which of the following is an Arrhenius base?

 

Al(OH)3

 

Ca(OH)2

 

KOH

 

more than one choice is correct

 

26.

 

A Brřnsted base is a(n)

 

proton donor

 

proton acceptor

 

OH- donor

 

OH- acceptor

 

27.

 

HIO3 + H2O = H3O+ + IO3-

Identify ALL Bronsted acids in the reaction above. Note that it is reversible.

 

HIO3

 

HIO3 and H3O+

 

H2O

 

H2O and HIO3

 

28.

 

The self-ionization of water produces OH- and

 

H2O

 

OH+

 

H3O-

 

H3O+

 

29.

 

You drink a liter of pure, neutral pH water. You have just consumed

 

10-7 moles OH- ions

 

10-7 moles H3O+ ions

 

only H2O molecules

 

more than one choice is correct

 

30.

 

A higher pH corresponds to

 

a higher [H+]

 

a lower [H+]

 

no change in [H+]

 

a lower [OH-]

 

31.

 

The molar concentration of H+ ions in a solution is 5.8 x 10-9. The pH is

 

9.00

 

5.80

 

between 8.00 and 9.00

 

between 9.00 and 10.00

 

32.

 

What would one of the products be if CuO reacted with HCl?

 

H2O

 

CuCl2

 

both of the above are correct

 

no correct response

 

33.

 

2Na(s) + H2SO4(aq) = Na2SO4(aq) + H2(g)

Write the reaction above in total ionic form and identify the spectator ion(s). The dissolved substances (designed by aq) are the only ones that dissociate completely into ions.

 

Na+

 

H+

 

SO42-

 

more than one choice is correct

 

34.

 

which of the following is NOT a characteristic of a solution?

 

the solvent can be a solid,liquid, or gas

 

the solute can be a solid, liquid, or gas

 

the mixture is heterogeneous

 

no correct response

 

35.

 

Which of the following decreases as the temperature of a water solution increases?

 

the solubility of a gas

 

the solubility of a solid

 

the saturation point of a solid

 

no correct response

 

36.

 

How many mL of a 6.00 M NaBr solution would have to be diluted with water to produce 500 mL of 0.500 M solution?

 

83.5

 

41.7

 

30.1

 

no correct response

 

37.

 

How many grams of KCl are needed to prepare 250 mL of 0.470 M solution?

 

18.6

 

62.6

 

31.2

 

8.76

 

38.

 

A salt water solution boils at 102oC. What will happen if more salt is added to the solution?

 

the osmotic pressure will decrease

 

the boiling point will decrease

 

the freezing point will decrease

 

no correct response

 

39.

 

which of the following can pass through a dialysizing membrane?

 

solvent molecules

 

colloid particles

 

small molecules

 

more than one choice is correct

 

40.

 

A + B = C + D + Heat
What would happen to the equilibrium above if the reaction vessel was heated?

 

the concentration of D would increase

 

the concentration of D would decrease

 

the concentration of B would decrease

 

no correct response

 

41.

 

HNO3 + H2O = H3O+ + NO3-
What is the Bronsted base in the reaction above? Note the reaction is reversible.

 

HNO3

 

H2O

 

H3O+

 

more than one choice is correct

 

42.

 

2H2O = H3O+ + OH-
Adding an Arrhenius acid to the equilibrium above would

 

increase the OH- concentration

 

decrease the OH- concentration

 

decrease the H2O concentration

 

no correct response

 

43.

 

If the pH of a solution is 9, what is the concentration of OH- ions?

 

1 x 10-9 mole/L

 

1 x 109 mole/L

 

1 x 105 mole/L

 

1 x 10-5 mole/L

 

44.

 

What products are produced when HCl reacts with NaOH?

 

salt

 

H2O

 

carbon dioxide gas

 

more than one choice is correct

 

45.

 

What is the likely source of the cation in Ca(NO3)2 salt which is produced by a neutralization reaction?

 

Ca(OH)2

 

CaCO3

 

HNO3

 

more than one choice is correct

 

46.

 

H2CO3 is an example of a _____ acid.

 

weak, diprotic

 

weak, monoprotic

 

strong, diprotic

 

strong, monoprotic

 

47.

 

A buffer solution has a pH of 8.6. A little acid is added to this solution. What is the probable pH of the new solution?

 

1.0

 

5.6

 

7.0

 

8.6

48.

 

Which of the following are made up of particles identical to electrons?

 

alpha rays

 

beta rays

 

gamma rays

 

more than one response is correct

 

49.

 

Radioactive decay is a process in which an unstable ________ changes energy states and emits radiation.

 

electron

 

proton

 

nucleus

 

neutron

 

50.

 

23793 Np is an alpha emitter. What is the element produced by the decay of Np-237?

 

U

 

Pa

 

Th

 

Pu

 

51.

 

4623V = ? + 4622Ti

What particle would complete the nuclear equation above?

 

alpha particle

 

beta particle

 

gamma ray

 

positron

 

52.

 

Sodium–24 has a half-life of 15.0 hours. Suppose you had a sample containing 0.010 moles of Na-24. How many hours would be required to reduce your sample to 6.25 x 10-4 moles?

 

120

 

60

 

45

 

30

 

53.

 

When high energy radiation knocks an electron out of an atom that it strikes, a _______ is formed.

 

free radical

 

daughter nucleus

 

radioisotope

 

fission reaction

 

54.

 

Iodine-123 can be used as a tracer specific for the thyroid gland. If a thyroid is NOT overactive, a ________ will form when I-123 is administered.

 

free radical

 

mutation

 

“cold spot”

 

“hot spot”

55.

 

Which of the following is NOT a particle released during radioactive decay?

 

alpha

 

beta

 

gamma

 

positron

 

56.

 

Lead-214 (Pb-214) undergoes radioactivce decay through beta emission.  What nucleus is produced from Pb-214?

 

214/83 Bi

 

214/81 Ti

 

215/82 Pb

 

No correct response

 

57.

 

After 60 minutes, a 10.0 g sample of Pb-194 is found to have only 1/16 the amount of radioactivity as it originally had.  What is the half-life of Pb-194?

 

45 minutes

 

30 minutes

 

15 minutes

 

10 minutes

 

58.

 

A gamma-ray emitting radioisotope used for medical purposes would be best suited for use as a

 

Diagnostic tracer

 

Therapeutic isotope

 

Metabolic inhibitor

 

No correct response

         


 

 

Answers:

  1. a
  2. d
  3. c
  4. b
  5. c
  6. c
  7. d
  8. a
  9. b
  10. a
  11. d
  12. c
  13. a
  14. c
  15. b
  16. c
  17. c
  18. b
  19. a
  20. c
  21. a
  22. d
  23. a
  24. c
  25. d
  26. b
  27. b
  28. d
  29. d
  30. b

 

  1. c
  2. c
  3. c
  4. c
  5. a
  6. b
  7. d
  8. c
  9. d
  10. b
  11. b
  12. b
  13. d
  14. d
  15. a
  16. a
  17. d
  18. b
  19. c
  20. b
  21. d
  22. b
  23. a
  24. c
  25. c
  26. a
  27. c
  28. a