Objectives

PSc.2.1.3–Compare physical and chemical

properties of various types of matter.

Physical Properties

Physical properties are characteristics that a sample of matter exhibits without any change in its identity.

This property can be observed and measured without changing the identity of the substance.

Examples of the physical properties of a chunk of matter include its:

solubility boiling point

and physical state (solid, liquid or gas)

electrical conductivity

color

melting point density

Physical Properties

magnetic

Salt is soluble in water.

Water boils at 100°C.

Physical Properties

Chemical Properties

Chemical Properties are properties of matter that describes a substance’s ability to participate in chemical reactions.

A chemical property describes how a substance changes into a new substance, either by combining with other elements or breaking apart into new substances. 5

Chemical Properties

Examples: – Reactivity- the ability of a substance to

combine chemically with another substance.

– Flammability- the ability of a substance to react in the presence of oxygen and burn when exposed to a flame.

– In general, the ability of a substance to react…to form…

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Chemical Properties

You can observe chemical properties only in situations in which the identity of the substance changes.

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Physical vs. Chemical Prop.

Classify the following properties as either chemical or physical.

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red color density flammability

solubility reacts with acid to form hydrogen

supports combustion

bitter taste melting point reacts with water to form a gas

reacts with a base to form water hardness boiling point

can neutralize a base luster odor

Physical vs. Chemical Prop.

Physical Properties– Red color – Density – Solubility– Bitter taste – Melting point – Hardness– Boiling point– Luster – Odor

Chemical Properties– Reacts with acid to form

hydrogen– Supports combustion– Reacts with water to

form a gas– Reacts with a base to

form water– Can neutralize a base

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Density

Density is the amount of matter (mass) contained in a unit of volume.

Styrofoam has a low density or small mass per unit of volume.

D

m

V

volume

massdensity

Density

Solving Density Problems–Cover the variable you are solving for– If you cover the top variable, multiple

the bottom ones

V

m

D

To solve for mass, multiply volume by density.

Density

Solving Density Problems– Cover the variable you are solving for– If you cover a bottom variable, take

the top variable and divide by the bottom

V

m

D

To solve for volume, take mass and divide by density.

Density

Calculate the mass for an object having a density of 19 g/mL and a volume of 5.0 mL.

GIVEN:

D = 19 g/mL

V= 5.0 mL

m = ?

WORK:

m = V x D

m = (19 g/mL) (5.0 mL)

m = 95 g

V

m

D

Calculate the volume for an object having a mass of 18 g and a density of 12 g/mL.

GIVEN:

m = 18 g

D = 12 g/mL

V = ?

WORK:

V = m ÷ D

V = (18 g) ÷ (12 g/mL)

V = 1.5 mL

V

m

D

Solve the following density problems.

1. The density of sugar is 1.59 g/cm3. Calculate the mass of sugar in 15.0 mL.(1 mL = 1 cm3)

23.9 g

Density

2. The density of helium is 0.178 g/L. Calculate the volume of helium that has a mass of 23.5 g.

132 L

Density

3. A 14.95 g sample of gold has a volume of 0.774 cm3. Calculate the density of gold.

19.3 g/cm3

Density

4. Balsa wood has a density of 0.12 g/cm3. What is the mass of a sample of balsa wood if its volume is 134 cm3?

16 g

Density

5. The density of ice at 0 °C is 0.917 g/cm3. Calculate the volume of 145 g of ice.

158 cm3

Density

Quiz

1. The temperature at which a solid becomes a liquid.

2. Ability of a substance to burn in the presence of oxygen.

3. Ability of a substance to combine chemically with another substance.

4. Mass per unit volume of a substance.

a. Melting pointb. Boiling pointc. Density d. Reactivity e. Flammability

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