Anything that has mass and takes up space.

Substances Versus MixturesSubstances- cannot

be separated by physical means.

Mixtures- can be separated by physical means

Pure SubstanceHas a uniform composition

All samples have identical properties like boiling point, melting pt., color, and density which can be used to identify the substance

**Review: Are these intensive or extensive properties?

ElementBuilding block for everything elseCannot be broken down or separated by

ordinary chemical or physical meansRepresented by chemical symbolEx. Iron, copper, silver, hydrogenRemember the diatomic

elements/molecules

Compounds2 or more different elements chemically

combinedHave different properties than

componentsSeparated into elements ONLY by

chemical means (chemical reactions) Definite composition (constant element

proportion)Represented by a chemical formulaEx. H2O (water), NaCl (sodium chloride)

MixtureA physical blend of 2 or more substancesCan be separated by physical means like

filtration, distillation, etc.Individual components keep their identifying

properties

Homogenous mixture

Components are uniformly distributed, there are parts but you cannot see them.

Also called solutions.Ex. Salt water, air,

brass

Heterogeneous mixture

Not uniform, you can see the parts

Can settle upon standing

Ex. Oil and vinegar, salt and pepper, soil, trail mix

Classify1. Which represent

substances?2. Which represent

mixtures?3. Which is an

element?4. Which is a

heterogeneous mixture?

CFU

Separation Techniques

MAGNETISMSORTING BY ATTRACTION OF CERTAIN

METALS TO A MAGNET.

FILTRATIONAn insoluble solid is removed from a liquid

mixture using a porous barrier (filter paper).

EVAPORATIONUsed to separate a soluble solid from a

solution.

DISTILLATIONhttp://www.youtube.com/watch?v=3VRi0KPGb3o

BASED ON DIFFERENCES IN BOILING POINTS, TWO LIQUIDS CAN BE SEPARATED WHEN ONE CHANGES TO A GAS AND THE OTHER REMAINS LIQUID.

CHROMOTOGRAPHYA separation technique based on the distance

the components of a mixture travel on the surface of

(or within) another material

A Homogeneous Mixture that can be separated by physical means.

Solution VocabularySolution – a

homogeneous mixture that consists of:

Solute – substance that dissolves, present in lesser amount

Solvent – thing that does the dissolving, present in greatest amount.

heating curvesSince solutions are NOT

pure substances, their heating curves will not be consistent…

The amount of solute varies in solutions, and so does the BP and FP.↑amount of solute, ↑BP, ↓FP

Shown is the heating curve for water. Water is a pure substance and always boils at 100°C and freezes at 0° (at standard pressure).

Dissociate – to separate into ionsElectrolyte-any

substance that dissociates and produces ions that conduct electricity. Ex. Salt (solute)

dissociates in water and the solution conducts electricity

Non-electrolyte – any substance that does not dissociate and therefore does not contain ions that conduct electricity.Ex. Sugar (solute)

does not dissociate in water so the solution does not conduct electricity

Dissolving a solvent surrounds a solute

Your body relies on water to dissolve the molecules in your body.Dissolution: the process by which one

substance (the solute) dissolves in another (the solvent)

Watch this:

Solublesubstance

dissolves in solvent

Ex. Sugar (solute) is soluble in water (solvent)

Insoluble substance does

not dissolve in solvent

Ex. Sand is insoluble in water

Miscible- describes two liquids that do mix

Immiscible – describes two liquids that do not mix

Solution Types

Solvent is Gas – ex. Air (nitrogen gas is the solvent)

Solvent is Liquid –ex. Sugar water (water is the solvent)WATER IS THE MOST COMMON

SOLVENT AND IS CALLED THE UNIVERSAL SOLVENT

Solvent is Solid – ex. Nitrinol (titanium dissolved in nickel, nickel is solvent, used to make braces)

It can dissolve many different substances.

SolubilityMaximum amount of solute that will

dissolve in a given amount of solvent at a given temp & pressure

Usually expressed as grams of solute per 100 g of solvent.

Affected by changes in the temperature or pressure

To Increase Solubility for a solid solute in a liquid solvent1. Increase temperature

of solvent Temp and solubility of a

solid are directly related

2. Increase surface area of solute (crush)

3. Agitate (stir or shake)

Not affected by changes in pressure

To Increase Solubility for a gas solute in a liquid solvent1. Decrease

temperature of solvent

Solubility of a gas and temperature are inversely related

2. Increase pressure Solubility of a gas and

pressure are directly related

Not affected by surface area of solute

Gas solubility

High Temp Low Temp

You want more gas particles in the liquid

Saturated Solutioncontains the

maximum amount of dissolved solute for a given amount of solvent at a specific temp and pressure.

Any point on the line represents a saturated solution.

Any point above the line, with solute visible, represents a saturated solution.

Unsaturated Solutioncontains less

dissolved solute for a given temp and pressure than a saturated solution

Any point below the line represents an unsaturated solution

Supersaturated Solutioncontains more

dissolved solute than a saturated solution at the same temp

Must heat a saturated solution, then slowly cool

Cannot be determined by JUST looking at a graph; you would need to know that it was saturated, heated, and cooled

Determining the solubility of a solutionAdd more solute. If…1)It dissolves, the

original solution was unsaturated (still more room).

2)It does not dissolve and falls to the bottom of the container, the original solution was saturated (no more room).

3)It crystallizes, the original solution was supersaturated (over full, past capacity).

Concentration is the amount of solute dissolved in a given amount of solvent.Concentrated Dilute

MolarityA unit of concentrationThe number of moles of solute dissolved in

1.00 L of solution.

Molarity (M) = Moles of solute Liter of solution

Practice ProblemWhat is the molarity if 2.0 moles of glucose

are added to 5.0 L of solution?

Changing the concentrationAdd more solvent

(yellow) decreases concentration

The amount of solute is the same, but now the solution volume has increased

How would you increae the concentration?

http://wps.prenhall.com/wps/media/objects/1053/1078985/ist/

ch03_11.html

Solution DilutionTo make a concentrated solution more

dilute use this formula M1V1 = M2V2

M1 = concentrated solution

V1 = amount of concentrated solution need to make dilute solution

M2= dilute solution

V2 – amount of diluted solution wanted.

PracticeHow many liters of 16.8M HCl is need to

make 2.5L of 3.5M HCl?

Practice problemMrs. Imamazing needs to make 12 liters of a

0.10 M HCl solution for her chemistry students to use in a lab. She finds a large bottle of 12.00 M HCl solution in the acid cabinet. Describe how she would make the solution?

Dalton’s Law of Partial Pressuresat constant volume & temperature, the

total pressure exerted by a mixture of gases is equal to the sum of the partial pressures

Total pressure = P gas1 + P gas2 + Pgas3….

Ptotal = P1 + P2 + P3….

Dalton’s LawWhat is the pressure of hydrogen, in atm, if it is

mixed with oxygen, which exerts a pressure of 2.1 atm, and the total pressure is 3.6 atm?

Dalton’s LawStandard Deviants