Lecture 2: Solutions And Their Behavior

Question 1

What is a solution?

Answer 1

A homogeneous mixture that consists of one or more solutes uniformly dispersed throughout a medium known as the solvent

Question 2

Solvent

Answer 2

Present in the larger amount

Question 3

Solute

Answer 3

Present in the smaller amount than the solvent

Question 4

Molality (m)

Answer 4

Moles solute/kg solvent

Question 5

Molarity (M)

Answer 5

Moles solute/L solution (more applicable to us)

Question 6

Molality is never…

Answer 6

Equal to molarity

Question 7

What is solubility?

Answer 7

Solubility is the amount of solute that will dissolve in a given amount of solvent

Question 8

Saturated

Answer 8

A saturated solution contains the maximum amount of a solute, as defined by its solubility

Question 9

Supersaturated

Answer 9

• this is NOT a stable system

- A solution contains more solute than allowed by the solubility

Question 10

Miscible

Answer 10

Two liquids are miscible if they are soluble in each other in all proportions
(I.e.: alcohol is miscible in water; oil is not miscible in water)

Question 11

Endothermic process

Answer 11

Energy flows into the system

Question 12

Exothermic process

Answer 12

Energy flows out of the system

Question 13

Heat

Answer 13

Transfer of energy into or out of a system caused by a difference in temperature

Question 14

What is Henry’s Law?

Answer 14

As pressure increases for gaseous solutes, solubility increases

Question 15

For liquid and solid solutes, P has…

Answer 15

A negligible effect

Question 16

As temperature increases, solubility of a gaseous solute ___

Answer 16

Decreases

Example: think about opening a warm can of soda pop—the carbon dioxide is less soluble and comes bubbling out

Question 17

As temperature increases, liquid and solid solubility ___

Answer 17

Increases

Question 18

What is the effect of temperature on the amount of gas dissolved?

Answer 18

Inverse relationship—the colder the liquid (i.e.: blood), the more gas that will dissolve in the liquid

Question 19

What does a colligative property depend on?

Answer 19

Depends only on the number of solute particles, not the identity of the solute particles

Question 20

What are 4 colligative properties?

Answer 20

1. The vapor pressure of a solution decreases with increasing solute concentration
2. The boiling point of a solution increases with increasing solute concentration
3. The freezing point of a solution decreases with increasing solute concentration
4. The osmotic pressure of a solution increases with increasing solute concentration

Question 21

Vapor pressure and increasing solute concentration

Answer 21

Decreases

Question 22

Boiling point and increasing solute concentration

Answer 22

Increases

Question 23

Freezing point and increasing solute concentration

Answer 23

Decreases

Question 24

Osmotic pressure and increasing solute concentration

Answer 24

Increases

Question 25

What is vapor pressure of a liquid?

Answer 25

Results from the most energetic molecules near the surface of the liquid escaping into the gas phase

Question 26

The vapor pressure of a solution (solutes added) is ___ than the vapor pressure of the pure solvent

Answer 26

Less than

Question 27

Raoult’s law

Answer 27

Gives the vapor pressure of a solution

Question 28

Boiling point

Answer 28

The temperature at which the vapor pressure of the material is equal to the ambient pressure

Question 29

Vapor pressure of a solution is decreased by…

Answer 29

The addition of nonvolatile solutes—a higher temperature is needed to drive the vapor pressure up to the point where it equals ambient pressure

Question 30

What increases the boiling point of a solution?

Answer 30

An increase in the concentration of solutes

Question 31

Freezing Point

Answer 31

The temperature at which the liquid phase of the material is in equilibrium with the solid phase

Question 32

Tonicity

Answer 32

The relative concentration of solutes in osmotic systems

Question 33

Isotonic =

Answer 33

Equal concentrations of particles

Question 34

Hypertonic =

Answer 34

Greater concentration of solute

Question 35

Hypotonic =

Answer 35

Lower concentration of solute

Question 36

Osmosis

Answer 36

Diffusion of water

Question 37

Diffusion occurs spontaneously from…

Answer 37

High concentration to low concentration

Question 38

What are colloids?

Answer 38

Not true solutions

-Might be supersized molecules (i.e.: proteins) or aggregate ions

Question 39

Colloidal particles cannot…

Answer 39

Be filtered and do not settle out of solution

Question 40

Examples of colloids

Answer 40

• blood
• milk
• jelly
• albumin