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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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