SOLUTIONS

Section 8.1

and 8.2

Solution

There are 2 components to every solution: Solute—A substance whose

particles are dissolved in a solution Solvent—The substance in which

the solute dissolves The solution takes the state of the

solvent

Solute

(getting dislvd)

Solvent

(doing disslvn)

Solution

(solute+solvnt)

Gas Gas Gas=Air

Liquid Gas Gas=Water in air

Gas Liquid Liquid=Soda

Liquid Liquid Liquid=Vinegar

Solid Liquid Liquid=Sugar water

Solid Solid Solid=Stainless steel

Substances can dissolve in water in 3 ways:

1. Dissociation—ionic compound separates into ions as it dissolves

2. Dispersion—process involves breaking into smaller pieces

3. Ionization—Neutral molecules gain or lose e-

PROPERTIES OF LIQUID SOLUTIONS

The 3 physical properties of a solution that vary from those of its solute & solvent are:

1. Conductivity

2. Freezing point

3. Boiling point

FACTORS AFFECTING RATES OF DISSOLVING

1. Surface Area

2. Stirring

3. Increasing Temperature

Star Questions

Particles that are dissolved in a solutionSoluteProcess in which particles dissolve by

breaking apart and scattering is calledDispersionName the 2 components of a solutionSolvent and solute

SOLUBILITY & CONCENTRATION

Solubility is the max amount of solute that dissolves in a given amount of solvent & a constant temp

usually expressed as g/100g of waterEx: 36g NaCl in 100g of 20ºC H2O

3 types of solutions

Saturated solns hold as much solute as solvent can hold at a given temp

Unsaturated solns have less than the max. amt of solute that can be dissolved

3 types of solutions

Supersaturated solns contain more solute than it normally hold at a given temp

if heat a saturated

soln what happens?

FACTORS AFFECTING SOLUBILITY

1. Polarity of solvent— “Like dissolves like” meaning a polar solvent will dissolve a polar solute or vice versaN2 & O2 are nonpolar molecules, they mix

well to give soln airH2O & NaCl are polar, = saltwaterH2O (polar) & Oil (nonpolar) do NOT MIX

2. Temperature—increases solubility of a solid in a liquid but a gasgas becomes less soluble (decreases) at higher temperatures (temp increases)

3. Pressure—Increasing pressure on a gasgas increases its solubility in a liquid

Which substance does not greatly increase as the temperature is increased?

NaCl Which substance

increases the most as temperature is increased?

KNO3

Which substance decreases in solubility, as the temperature is increased?

Ce2(SO4)3

If 50g of KCl are dissolved in 100g of water at 50oC, what type of solution is formed?

Supersaturated Which substance

is the most soluble at 0oC?

NaNO3

Which substance is least soluble at 0oC?

KClO3

Which 2 substances have the same solubility at 60oC?

NaCl and K2Cr2O7

At 30oC which substance, Pb(NO3)2 or KNO3, can form the more concentrated solution?

Pb(NO3)2

Above line supersaturated

Below line unsaturated

On line saturated

Star Questions

Name 3 physical properties of solution1. Conductivity2. Freezing point 3. Boiling pointName 3 factors that affect rate of dissolving1. Surface Area2. Stirring 3. Increasing TemperatureName the 3 types of solutions Supersaturated, saturated, unsaturated

Solubility Curves of Pure Substances

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

0 10 20 30 40 50 60 70 80 90 100

Temperature/Celsuis

gra

ms

solu

te p

er 1

00 g

ram

s H

2O

KI

NaNO3

KNO3

Ce2(SO4)3

NH3

KClO3

NH4Cl

KCl

NaCl

1.Which of the salts shown on the graph is the least soluble in water at 10oC?KClO3

2. Which of the salts shown on the graph has the greatest increase in solubility as the temperature increases from 30 degrees to 60 degrees?KNO3

3. Which of the salts has its solubility affected the least by a change in temperature?NaCl

4. At 20oC, a solution of sodium nitrate contains 100 grams of solute in 100 ml of water. What type of solution is formed?supersaturated

5. At what temperature do saturated solutions of potassium nitrate and sodium nitrate contain the same weight of solute per 100 mL of water?~71oC

Solubility Curves of Pure Substances

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

0 10 20 30 40 50 60 70 80 90 100

Temperature/Celsuis

gram

s so

lute

per

100

gra

ms

H2O

KI

NaNO3

KNO3

Ce2(SO4)3

NH3

KClO3

NH4Cl

KCl

NaCl

6. What two salts have the same degree of solubility at approximately 19oC?

NaCl & NH4Cl or KNO3 & KCl7. How many grams of potassium chlorate must be added to water to produce a saturated solution at

50oC?~21g

8. Thirty grams of KCl are dissolved in 100 mL of water at 45oC. What type of solution is formed?

unsaturated9. What temperature is needed for 30. grams of

KCl to dissolve in 100 mL of water in order form a saturated solution?

~10OC10. What state of matter is NH3?

GasHow do you know?

Decreased solubility as temperature increasedAre the following solutions saturated, unsaturated or supersaturated

11. a) 40. g of KCl in 100 mL of water at 80oC un

11. b) 120. g of KNO3 in 100 mL of water at 60oCsuper

11. c) 80. g of NaNO3 in 100 mL of water at 10oCsaturated

Use the different colors for each compound!

CompoundTemperature Temperature Temperature Temperature

0oC 20oC 60oC 100oC

(red) Ba(OH)2 1.67 g 3.89 g 20.94 g 101.40 g

(blue) CuSO4 23.10 g 32.00 g 61.80 g 114.00 g

(yellow) KCl 28.0 g 34.2 g 45.8 g 56.30 g

(green) NaNO3 73.0 g 87.6 g 122.0 g 180.00 g

0

20

40

60

80

100

120

140

160

180

0 20 40 60 80 100

Temperature (oC)

So

luli

bil

ity (

g/1

00g

of

wate

r)