matter what it is all about. chemistry – matter unit what is matter? what is the organization of...

MATTER

What it is all about

Chemistry – Matter Unit

• What is matter?

• What is the organization of matter?

• What is the nature of matter?

Mixtures Pure Substances

MATTER

Can the matter be separated by physical means?

Heterogeneous

Homogeneous

Compounds

Elements

Separation by chemical meansConstant composition

Matter

Matter is anything that occupies space and has mass.

The particle theory of matter.

The particle theory states that…

all matter is made from particles

different particles have different properties

particles are constantly in motion

States of Matter

A solid has a definite shape and volume.

A liquid has a definite volume but no definite shape.

A gas has neither a definite volume or shape.

Gas Liquid Solid

SOLIDS

• the attraction between particles is strong so the matter holds its shape. The particles are still moving, but they are not able to slide past each other

LIQUIDS

• the attractive forces are not as strong. The particles

are able to move past each other and slide around

GAS

• the attraction between particles is so weak that they fly in every direction filling the container that they are held

vaporization

condensation

subl

imat

ion

subl

imat

ion

melting

solidification (freezing)

Properties of Matter

Physical Properties:

• a quality of a substance that can be observed or measured without changing the substance’s chemical composition

Examples: color, texture, boiling point, density, mass etc…

Chemical properties

• Properties that do change the chemical nature of matter • Properties the matter exhibits when chemical change occurs

Ex. oxidation, flammability, corrosiveness, pH, reactivity

Physical Properties Subcategories

• Extensive Properties depend upon the amount of matter that is present.

Ex. Length, mass, volume, heat …etc

• Intensive Properties do not depend on the amount of matter present. These properties are the same for a given substance regardless of how much of the substance is present.

Ex. Color, density, melting point, ductility, temp… etc

• Boiling point• Specific gravity (at constant temperature)• Surface tension• Viscosity (at constant pressure and temp.)• Freezing point• Solubility in water (hot/cold)• Density• Melting point• Mass• Volume• Specific heat capacity• Heat • Temperature

Examples of physical properties

Density

• the mass of a substance per a specific amount of volume

Density = mass

volume

• The mass and volume are directly proportional. If one increases the other increases

Physical and chemical change

• Physical change– the altering of the physical form but not

composition of matter– ex. Pounding, pulling, changes of state

• Knowledge of physical change leads to…– the understanding of separation of mixtures

– ex. Distillation, crystallization, chromatography, filtration

Chemical change

• Chemical change– change in which the matter is converted into

matter with different composition and properties

Indicators of chemical change

1. heat and/or light energy– Energy changes within the system

2. Production of gas

- release of gas from the system

3. Formation of a precipitate

- when two (or more) solutions are put together an insoluble solid is produced

4. Color change

- the system changes color

- not always an indicator of chemical change (can be physical

Mixtures Pure Substances

MATTER

Can the matter be separated by physical means?

Heterogeneous

Homogeneous

Compounds

Elements

Separation by chemical meansConstant composition

MIXTURES

mixture: - combination of two or more kinds

of matter each of which retains its own composition and properties

- physical blend of two or more substances

heterogeneous mixture: - a mixture containing substances that are not evenly distributed

- different from point to pointex. granite ---> quartz, feldspar, and mica

More of Mixtures:

Phase

• mixtures that are obviously heterogeneous and have separate, distinct parts

Ex. Oil forming layers in water is another

Interface – the region where two or more phases meet

M o M

homogeneous mixture - a mixture containing substances that are

uniformly distributed with the particles blended completely

- composition and properties are uniform throughout

- also called solutions (mixed on a scale of individual particles) ex. I molar copper II sulfate

• To the eye, the mixture appears to be pure substance.

SolutionsSolutions(Homogeneous Mixtures)(Homogeneous Mixtures)

Can you tell the difference?Can you tell the difference?

Parts of a Solution• SOLUTE – the part of

a solution that is being dissolved (usually the lesser amount)

• SOLVENT – the part of a solution that dissolves the solute (usually the greater amount)

• Solute + Solvent = Solution

Solute Solvent Example

solid solid Brass: Copper and Zinc

solid liquid Seawater: NaCL in water

gas solid Moth balls: naphthalene

liquid liquid Ethyl alcohol and water (miscible)

gas liquid SODA: CO2 gas in water

gas gas AIR: O2 gas, N2 gas

DefinitionsDefinitions

Solutions can be classified as Solutions can be classified as saturatedsaturated or or ununsaturatedsaturated..

A A saturatedsaturated solution contains the solution contains the maximum quantity of solute maximum quantity of solute that dissolves at that that dissolves at that temperature.temperature.

An An unsaturatedunsaturated solution contains solution contains less than the maximum less than the maximum amount of solute that can amount of solute that can dissolve at a particular dissolve at a particular temperaturetemperature

DefinitionsDefinitionsSUPERSATURATED SOLUTIONSSUPERSATURATED SOLUTIONS contain more solute contain more solute

than is possible to be dissolved in a given amount of than is possible to be dissolved in a given amount of solventsolvent

Supersaturated solutions are unstable. Supersaturated solutions are unstable.

-- the supersaturation is only temporary-- the supersaturation is only temporary

-- need to warm the solvent so that it will dissolve -- need to warm the solvent so that it will dissolve moremore

-- then need to cool the solution slowly-- then need to cool the solution slowly

http://www.youtube.com/watch?v=jVhPZg3dxIg http://www.youtube.com/watch?v=HnSg2cl09PI&feature=related

• Some mixtures are in-between heterogeneous mixtures and homogeneous solutions.

Somewhere In Between

• suspension • has clumps that stay floating• filtering a suspension will usually separate the particles.

• colloid • has very small clumps that almost make a solution • the clumps are so small that they pass through most filters

• milk is an example of a colloid.

• emulsion • the clumps of particles are held with an emulsifying agent. • mayonnaise as an example

Define the following wordssolubility. 

 Miscible 

Immiscible  

Separation of Mixturestypes of…

• Filtration– Separation of mixture on the basis of

differences in the size of the particles– Mostly used to separate solids from liquids (but

filtration is used to separate all phases of matter from one another)

Ex. Air filters separate gas (air) from solid (dirt particles)

http://www.youtube.com/watch?v=nJVbFIIycKo

• Distillation– Based on the tendency of a substance to

vaporize (turn to a gas)– Based on boiling point differences– The substance in the mixture with the lowest

boiling point will vaporize first from the mixture

Ex. Crude oil http://www.youtube.com/watch?v=26AN1LfbUPc

• Chromatography– Based on the differences in solubility– Two types Gas and Paper– Mixture separates as it travels (most soluble

separates first)

Solute – substance that gets dissolved

Solvent – substance that does the dissolving

Ex. Separating ink in a marker http://www.youtube.com/watch?v=OKxRx0ctrl0&feature=related

http://www.youtube.com/watch?v=LY44uD2miYM

• Crystallization– Separation of the mixture is based on

solubility differences– Temperature changes within the mixtures

change solubility of parts of the mixture

Solubility – the amount of a solute that is able to dissolve in a given amount of solvent

Ex. Rock candy http://www.youtube.com/watch?v=l_USYub3djY&feature=related

Concentration: • amount of solute in a given amount of solvent (can be determined quantitatively)

Dilute: • a solution with a small amount of solute per solvent amount (relative term)

Concentrated: • a solution with a large amount of solute per solvent amount (relative term)

BOTH DILUTE AND CONCENTRATED ARE QUALITATIVE

SOLUTION CHEMISTRY

Concentration of SoluteConcentration of SoluteConcentration of SoluteConcentration of Solute

The amount of solute in a solution is The amount of solute in a solution is

given by its given by its concentrationconcentration.

Molarity (M) = moles soluteliters of solution

The concentration of a solution is said to be its molarity.

Ex. 1 M CuSO4

“1 molar copper II sulfate