Definitions

• Solution - Solution - homogeneous mixture

Solvent Solvent - present in greater amount

Solute Solute - substance being dissolved

Solutions

• What the solute and the solvent are determines–whether a substance will dissolve. –how much will dissolve.

• A substance dissolves faster if it is stirred or shaken.–The particles are made smaller.–The temperature is increased.

Why?

Solution = Solute + Solvent

• Solute - gets dissolved

• Solvent - does the dissolving– Aqueous (water)

– Tincture (alcohol)

– Amalgam (mercury)

– Organic• Polar• Non-polar

Dental filling

Nightmare on White StreetChem Matters, December 1996

Solution Definitionssoluti

on:

alloy:

solvent: the substance that dissolves the solute

water salt

a homogeneous mixture

-- evenly mixed at the particle level

-- e.g., salt water

a solid solution of metals

-- e.g., bronze = Cu + Sn; brass = Cu + Zn

“will dissolve in”

refers to two gases or two liquids that forma solution; more specific than “soluble”

-- e.g., food coloring and water

miscible:

soluble:

Types of Solutions

Solute Solvent Solution

Gaseous Solutions

gas

liquid

gas

gas

air (nitrogen, oxygen, argon gases)

humid air (water vapor in air)

Liquid Solutions

gas

liquid

solid

liquid

liquid

liquid

carbonated drinks (CO2 in water)

vinegar (CH3COOH in water)

salt water (NaCl in water)

Solid Solutions

liquid

solid

solid

solid

dental amalgam (Hg in Ag)

sterling silver (Cu in Ag)Charles H.Corwin, Introductory Chemistry 2005, page 369

As size , rate

As To , rate

3. mixing

Factors Affecting the Rate of Dissolution

1. temperature

2. particle size

4. nature of solvent or solute

More mixing, rate

Classes of Solutionsaqueous solution:

water = “the universal solvent”

solvent = water

amalgam: solvent = Hg

e.g., dental amalgam

tincture: solvent = alcohol

e.g., tincture of iodine (for cuts)

organic solution: solvent contains carbon

e.g., gasoline, benzene, toluene, hexane

Non-Solution Definitions

insoluble: “will NOT dissolve in”

e.g., sand and water

immiscible: refers to two gases or two liquids that will NOT form a solution

e.g., water and oil

suspension: appears uniform while being stirred, but settles over time

Water

HOT

Solubility

A B

Before

Water

COLD

Add 1 drop of red food coloring

Miscible – “mixable”

two gases or two liquids that mix evenly

Experiment 1:

Water

HOT

AFTER

Water

COLD

A B

Solubility

Water Water

Oil

T30 sec

AFTER

Before

Add oil to water and shake

Immiscible – “does not mix”

two liquids or two gases that DO NOT MIX

Experiment 2:

T0 sec

Muddy Water: Dissolved Solids

Muddy

Water

T1 min T5 min

AFTER

Water

Before

Add soil to water, shake well, and allow to settleExperiment 3:

Dissolved solids can be calculatedas a percentage:

v/v (volume/volume)w/v (weight/volume)w/w (weight/weight)

5 mL solid / 95 mL water

5% v/v soil in water

5 mL / 100 mL = 5%

Muddy Water: Flocculation

Muddy

Water

T1 min T15 min

AFTER

Water

Before

Add soil to water, shake well, and allow to settleExperiment 4:

Muddy

Water

T1 min T5 min

Water

BeforeAFTER

NO Flocculation material WITH Flocculation material

Al2(SO4)3 + 3 Ca(OH)2 2 Al(OH)3 + 3 CaSO4

Centrifugation

• Spin sample very rapidly: denser materials go to bottom (outside)

• Separate blood into serum and plasma– Serum (clear)– Plasma (contains red blood

cells ‘RBCs’)• Check for anemia (lack of iron)

Blood

RBC’s

Serum

A

AFTER

Before

B C