Chapter 13 - Properties of Solutions Flashcards Preview

Chemistry 1040 - NSULA Fall 2016 > Chapter 13 - Properties of Solutions > Flashcards

Flashcards in Chapter 13 - Properties of Solutions Deck (61)
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1
Q

Define solutions.

A

homogeneous mixtures of two or more pure substances

2
Q

Define solute.

A

the minor component in a solution; dissolved in the solvent

3
Q

Define solvent.

A

a substance that dissolves a solute, resulting in a solution

4
Q

What does the ability of substances to form solutions depend on?

A

natural tendency toward mixing, intermolecular forces

5
Q

How is the mixing of gases a spontaneous process?

A

each gas acts as if it is alone to fill the container

6
Q

How does mixing increase entropy?

A

it causes more randomness in the position of molecules

7
Q

How is the formation of solutions affected by mixing?

A

it is favored by the increase in entropy which accompanies it

8
Q

Which intermolecular force of attraction exists between solute and solvent?

A

any of the intermolecular forces of attraction can exist between solute and solvent molecules

9
Q

What must happen to solute-solute interactions when making a solution?

A

solute-solute interactions must be overcome

10
Q

What must happen to solvent-solvent interactions when making a solution?

A

solvent-solvent interactions must be overcome

11
Q

When do solvent-solute interactions occur?

A

solvent-solute interactions occur as the particles in a solution mix

12
Q

What must be true for a reaction to occur?

A

ΔHmix must be close to the sum of ΔHsolute and ΔHsolvent

13
Q

If a substance disappears when it comes in contact with a solvent, has it definitely dissolved?

A

no, it may have reacted

14
Q

What is the opposing process to solution-making?

A

crystalization

15
Q

What is true of a saturated solution?

A

When the rate of the opposing processes is equal, additional solute will not dissolve unless some crystallizes from solution.

16
Q

What is true of an unsaturated solution?

A

If we have not yet reached the amount that will result in crystallization, we have an unsaturated solution.

17
Q

Define solubility.

A

the maximum amount of solute that can dissolve in a given amount of solvent at a given temperature

18
Q

What is true of a supersaturated solution?

A

In supersaturated solutions, the solvent holds more solute than is normally possible at that temperature.

19
Q

How can crystallization be stimulated in a supersaturated solution?

A

by adding a “seed crystal” or scratching the side of the flask

20
Q

Supersaturated solutions are (common/uncommon) solutions.

A

uncommon

21
Q

List three factors that affect solubility.

A
  • solute-solvent interactions
  • pressure (for gaseous solutes)
  • temperature
22
Q

The (stronger/weaker) the solute-solvent interaction, the (greater/less) the solubility of a solute in a solvent.

A

stronger, greater

23
Q

The (larger/smaller) the gas, the (more/less) soluble it will be in water.

A

larger, more

24
Q

Polar organic molecules dissolve in water (better/worse) then nonpolar organic molecules.

A

better

25
Q

Hydrogen bonding (increases/decreases) solubility, since C-C and C-C (are/are not) very polar.

A

increases, are

26
Q

Define miscible.

A

liquids that mix in all proportions

27
Q

Define immiscible.

A

liquids that do not mix in one another

28
Q

Because hexane is nonpolar and water is polar, they are (miscible/immiscible).

A

immiscible

29
Q

What is the biological significance of solubility?

A

Fat soluble vitamins are nonpolar and are readily stored in fatty tissue of the body; water soluble vitamins need to be included in the daily diet.

30
Q

The solubility of solids and liquids (are/are not) appreciably affected by pressure.

A

are not

31
Q

Gas solubility (is/is not) affected by pressure.

A

is

32
Q

What relationship does Henry’s Law describe?

A

the solubility of a gas is proportional to the partial pressure of the gas above the solution

33
Q

For (all/most/no) solids, as temperature increases, solubility increases.

A

most

34
Q

For (all/most/no) gases, as temperature increases, solubility decreases.

A

all

35
Q

List six units of concentration used for solutions.

A
  • Mass percentage
  • Parts per million (ppm)
  • Parts per billion (ppb)
  • Mole fraction
  • Molarity
  • Molality
36
Q

How is mass percentage calculated?

A

the ratio of the mass of the solute to the total solution mass, multiplied by 100

37
Q

How is parts per million calculated?

A

the ratio of the mass of the solute to the total solution mass, multiplied by 10^6

38
Q

How is parts per billion calculated?

A

the ratio of the mass of the solute to the total solution mass, multiplied by 10^9

39
Q

How is mole fraction calculated?

A

the ratio of moles of a substance to the total number of moles in a solution

40
Q

How is molarity calculated?

A

the ratio of moles of solute to the total liters of solution

41
Q

How is molality calculated?

A

the ratio of moles of solute to the total kilograms of solvent

42
Q

Molality (does/does not) vary with temperature.

A

does not

43
Q

Molarity (does/does not) vary with temperature.

A

does

44
Q

What must be used to convert between molality and molarity?

A

the density of the solution

45
Q

What do colligative properties depend on?

A

the quantity of the solute particles

46
Q

List four colligative properties.

A
  • Vapor-pressure lowering
  • Boiling-point elevation
  • Freezing-point depression
  • Osmotic pressure
47
Q

The vapor pressure of a solution is (higher/lower) then that of the pure solvent.

A

lower

48
Q

What relationship does Raoult’s Law describe?

A

The vapor pressure of a volatile solvent over the solution is the product of the mole fraction of the solvent times the vapor pressure of the pure solvent.

49
Q

In ideal solutions, it (is/is not) assumed that each substance will follow Raoult’s Law.

A

is

50
Q

Why is boiling point raised in solutions?

A

vapor pressures are lowered

51
Q

What happens to the freezing point of a solution as the boiling point is raised?

A

the freezing point is lowered

52
Q

What is the relationship between boiling point elevations/freezing point depression and molality?

A

The change in temperature is directly proportional to molality.

53
Q

What does the van’t Hoff Factor describe?

A

it takes into account dissociation in solution

54
Q

Define semipermeable membrane.

A

a membrane that allows some smaller particles to pass through but blocks larger particles

55
Q

Define osmosis.

A

the net movement of solvent molecules from solution of low to high concentration across a semipermeable membrane

56
Q

Define osmotic pressure.

A

the applied pressure to stop osmosis

57
Q

If two solutions seperated by a semipermeable membrane have (the same/different) osmotic pressure, no osmosis will occure.

A

the same

58
Q

Define colloid suspension.

A

a suspension of particles larger then individual ions or molecules but too small to be settled out by gravity

59
Q

Define Tyndall effect.

A

the ability of colloid suspensions to scatter rays of light

60
Q

What does an emulsifier do?

A

it causes something that does not normally dissolve in a solvent to do so

61
Q

Define Brownian Motion.

A

motion of colloids due to numerous collisions with the much smaller solvent