Chapter 3

“Matter – Properties & Change”

Adapted from the presentation created by:

Stephen L. Cotton

Section 3.1Properties of Matter

OBJECTIVES:

•Identify properties of matter as extensive or intensive.

Section 3.1Properties of Matter

OBJECTIVES:

•Define physical property, and list several common physical properties of substances.

Section 3.1Properties of Matter

OBJECTIVES:

•Differentiate among three states of matter.

Section 3.1Properties of Matter

OBJECTIVES:

•Describe a physical change.

MatterMatter is anything that: a) has mass, and b) takes up space

Mass = a measure of the amount of “stuff” (or material) the object contains (don’t confuse this with weight, a measure of gravity)

Volume = a measure of the space occupied by the object

Describing Matter

Properties used to describe matter can be classified as:

1) Extensive – depends on the amount of matter in the sample

- Mass, volume, calories are examples

2) Intensive – depends on the type of matter, not the amount present

- Hardness, Density, Boiling Point

Properties are…Words that describe matter (adjectives)

Physical Properties- a property that can be observed and measured without changing the material’s composition.

Examples- color, hardness, m.p., b.p.

Chemical Properties- a property that can only be observed by changing the composition of the material.

Examples- ability to burn, decompose, ferment, react with, etc.

States of matter1) Solid- matter that can not flow (definite shape) and has

definite volume.

2) Liquid- definite volume but takes the shape of its container (flows).

3) Gas- a substance without definite volume or shape and can flow.

• Vapor- a substance that is currently a gas, but normally is a liquid or solid at room temperature. (Which is correct: “water gas”, or “water vapor”?)

States of MatterStates of Matter

Solid

Liquid

Gas

Definite Volume?

YES

YES

NO

Definite Shape?

YES

NO

NO

Result of a Temperature Increase?

Small Expans.

Small Expans.

Large Expans.

Will it Compress?

NO

NO

YES

4th state: Plasma - formed at high temperatures; ionized phase of matter as found in the sun

Three Main States of matter

Solid Liquid Gas

Melt Evaporate

CondenseFreeze

Copper Phases - Solid

Copper Phases - Liquid

Copper Phases – Vapor (gas)

Physical vs. Chemical ChangePhysical change will change the visible appearance, without changing the composition of the material.

•Boil, melt, cut, bend, split, crack, phase changes

• Is boiled water still water?Can be reversible, or irreversible

Chemical change - a change where a new form of matter is formed – chemical reaction.

•Rust, burn, decompose, ferment

Physical or chemical change?

Physical or chemical change?

Physical or chemical change?

Physical or chemical change?

Physical or chemical change?

Physical or chemical change?

Physical or chemical change?

Physical or chemical change?

Physical or chemical change?

Physical or chemical change?

The law of conservation of mass

Mass is neither created nor destroyed in a chemical reaction – it is always conserved.

massreactants = massproducts

Example

Mercury oxide is a red, solid powder at room temperature. When heated, it decomposes to liquid mercury and oxygen gas.

EX: A 10.00 g sample of mercury oxide is heated in a closed flask until it is fully converted to liquid mercury and oxygen. The mass of the liquid mercury is 9.26 g. What is the mass of the oxygen formed in the reaction?

Solution: Law of conservation of mass

massreactants = massproducts

massmercury oxide = massliquid mercury + massoxygen

10.00 g mercury oxide = 9.26 g mercury + massoxygen

massoxygen = 10.00 g – 9.26 g

massoxygen = 0.74 g

Try this now please

A fuel cell engineer conducted an experiment to separate water into oxygen and hydrogen gas.

10.0 g of hydrogen gas and 79.4 g of oxygen gas were collected.

How much water was originally involved in the process?

89.4 g water

Try this now please

15.6 g of sodium was placed in a reactor with excess chlorine gas.

When the reaction is complete, a 39.7 g sample of NaCl was obtained.

How many grams of chlorine gas reacted?

24.1 g of chlorine gas

Challenge

Create an experiment to demonstrate the law of conservation of mass.

Materials:

Baking soda

Vinegar

Small plastic cup

Quart-size Ziplock bags