Matter-Properties

and ChangesI will distinguish between physical and chemical properties

I will classify matter by composition: element, compound or mixture

I will identify observable characteristics of chemical reactionsI will explain the fundamental law of conservation of mass

Properties of Matter

I will identify the characteristics of a substance

I will distinguish between physical and chemical properties

I will differentiate among the physical states of matter

Substances Matter that has a uniform and unchanging

composition Aka pure substance

Example 1 Table Salt Always 100% sodium chloride

Example 2 Water H2O

NOT AN EXAMPLE Sea water Samples vary by location Amount of salts, water, dissolved substances

Physical Properties

A characteristic that can be observed or measured WITHOUT changing the sample’s composition

Density

Color

Odor

Taste

Hardness

Melting point

Boiling point

Examples-Physical Properties

Salt (sodium chloride) Forms solid white crystals at room

temperature Unique salty taste

Oxygen Colorless Gas at 25 degrees Celsius Melting point -218 degrees Celsius Boiling point -183 degrees Celsius Density 0.0014 g/cc

Extensive Properties

Dependent upon the amount of substance present

Examples Mass Volume Length Weight

Intensive Properties

Independent of the amount of the substance present

Examples

Chemical Properties

The ability of a substance to combine with or change into one or more other substances

And/Or

The inability of a substance to change into another substance

Example Iron forms rust when combined with air Iron + Nitrogen (at room temperature) = no

chemical change

Observing Properties of Matter

Every substance has its own unique set of physical and chemical properties

May vary depending on conditions of immediate environment Room temperature, standard pressure, etc.

Example

Copper

Physical Properties Chemical Properties

Reddish brownShinyMalleable (easily shaped)Ductile (drawn into wire)Conducts heat/electricityDensity 8.92 g/ccMelting Point 1085 ℃Boiling Point 2570 ℃

Forms green copper carbonate compound when in contact w/ moist air

Forms new substances when combined with nitric and sulfuric acids

Forms a deep blue solution when in contact with ammonia

States of matter

Solid

Liquid

Gas

Plasma FUN FACT: (only occurs

naturally on Earth in the

form of lightening bolts!)

PHYSICAL PROPERTY!!!!!

Solids A form of matter that has its

own definite shape and volume. Examples

Wood Iron Paper Sugar

Particles are VERY tightly packed

Will only expand SLIGHTLY when heated

Does NOT conform to shape of container

Incompressible Volume stays the same Example

Wax (moldable) but volume doesn’t change

Liquids

A form of matter that flows, has constant volume, and takes the shape of its container

Examples Water Blood Mercury

Virtually incompressible

Tend to expand when heated

Liquid Particles NOT rigidly held in place less closely packed than

solids Are able to move past each

other

Gases A form of matter that flows

to CONFORM to the shape of its container and fills the ENTIRE volume of its container

Examples Neon

Lighted signs Methane

Cooking Air

Mixture of gases

Particles are VERY far apart

EASILY compressed

A substance NATURALLY in the gaseous state at room temperature

RELATED TERMS Vapor

The gaseous state of a substance that is a SOLID or LIQUID at room temperature

Example steam

Quick Think

Describe the characteristics that identify a sample of matter as being a substance.

Classify each of the following as a physical or chemical property Iron and oxygen form rust Iron is more dense than

aluminum Magnesium burns brightly

when ignited Oil and water do not mix Mercury melts at -39 ℃

Using what you know about the compressibility of gases, explain why the oxygen in a SCUBA tank is compressed.

Create a table that describes the three common states of matter in terms of their shape, volume, and compressibility.

Quick Think- Check

The sample of matter must have a uniform and unchanging composition to be a substance.

Properties Chemical (rust) Physical (density) Chemical (burning) Physical (mixing) Physical (melting)

point)

Particles of gas are spaced apart and are easily compressed. Therefore, it is possible to put a significant volume of oxygen in the tank, which allows the diver to remain under water longer!Solid Liquid Gas

Definite volume Definite volume Fills volume of container

Definite shape Fills container shape

Takes shape of container

Incompressible Virtually incompressible

Compressible

Changes in Matter

I will define physical change and list several common physical changes

I will define chemical change and list several indications that a chemical change has taken place

I will apply the law of conservation of mass to chemical reactions

Physical CHANGES

Alter a substance WITHOUT changing its composition

Might result in dramatically different appearance (yet leave the composition of the substance unchanged)

Examples Crunching up a piece of aluminum foil Cutting a sheet of paper Breaking a crystal Phase changes (solid, liquid, gas)

Key words of Physical Changes

Bend

Grind

Crumple

Split

Crush

Chemical CHANGES

A process that involves one or more substances changing into a NEW substance New substance

Formed in reaction Different compositions — than original substance(s) Different properties — than original substance(s)

Example Fermentation of juice, sugars, and other ingredients

(making wine) Rusting of iron (a chemical combo of iron and

oxygen)

Chemical CHANGES

Commonly referred to as a chemical reaction Reactants

Starting substances Products

New substances

Example Reactants = Iron, Oxygen Product = rust

Key Words of Chemical Changes

Explode

Rust

Oxidize

Corrode

Tarnish

Ferment

Burn

Rot

The LAW of Conservation of Mass

Mass is neither created nor destroyed during a chemical reaction

Mass is conserved

Mass of Reactants = Mass of Products

Conservation of Mass Problem

Known Mass mercury (II)

oxide = 10.0g Mass liquid mercury =

9.26g

Unknown Mass formed oxygen =

? g

Mass Reactants = Mass Products

Mercury (II) oxide = Mercury + Oxygen

10.0g = 9.26g + ?

0.740 g of Oxygen formed

Quick Think

Describe the results of a physical change and 3 examples. Repeat with chemical change.

A friend tells you, “because composition does not change during a physical change, the appearance of a substance does not change.” Is your friend correct? Explain WHY?

Solve each of the following In the complete

reaction of 22.99 g of sodium with 35.35 g chlorine, what is the mass of the sodium chloride formed?

A 12.2 g sample of X reacts with a sample of Y to form 78.9 g XY. What way the mass of Y that reacted?

Quick Think-Check

During a physical change a substance is altered but its composition does not change. EX melting, freezing, boiling, bending, tearing

During a chemical change the composition of a substance IS altered. EX color change, odor, temperatures change, formation of gas or solid from a liquid.

The statement is false. Composition doesn’t change but a change in appearance often accompanies a physical change.

58.44g of sodium chloride

66.7 g of Y