Chapter 3 – Matter and Energy
Denotes – not necessary to copy
Matter
States of Matter: solid – liquid – gas
increasing energy >>>>
50mL of ice has less energy than 50mL of water.
50mL of water has less energy than 50mL of steam.
The energy of the particles in the 50mL of H2O increases
as it goes from solid-liquid-gas.
There are two questions that can be answered to
determine the state of matter.
1. Does the matter take the shape of its container?
2. Does the volume of the matter remain constant?
If the answer to both questions is yes; the state of the
matter is a gas.
If the answer to both questions is no; the state of the
matter is a solid.
If the sample of matter takes the shape of its container
but has constant volume; the state of the matter is a
liquid. A liquid shares one property of each other the
other states of matter.
Probably the most important real world lesson involving
states of matter is that a liquid CANNOT be compressed.
When a liquid gets in a place (engine cylinder) where a
gas is to be compressed, something had to give and it
usually causes severe engine damage. This could happen
if a car runs through deep water.
Change of State Chart
Change from: Solid
Liquid
Gas
Solid to a
Melting
Sublimation
Liquid to a
Freezing
Vaporization
Gas to a
Deposition Condensation
Note: Vaporization includes evaporation (when particles
at the surface gain enough energy to transition from
liquid to gas) and boiling (particles throughout the
substance gain enough energy to transition from liquid to
gas)
Physical and Chemical Properties and Changes
Physical property – a property based on the state of a
substance.
All of the changes listed in the chart above are physical
changes. Also any change that does not involve a
substance becoming a different substance is a physical
change. Cutting a paper into pieces is a physical change.
Grating cheese is a physical change.
Chemical property – a property based on the reactivity
of a substance.
A chemical change is called a chemical reaction. The
requirement for a change to be a chemical change is the
formation of at least one new substance. The nail rusted
away to nothing. This indicates a chemical reaction; Fe +
O2 Fe2O3
Note: Burn words typically indicate a chemical change
has occurred. Scorched, burnt, bake, roast, sear, toast,
etc.
Classification of Matter
Pure Substance – the word substance implies pure
substance in chemistry.
Element – a pure substance that cannot be broken down
into simpler substances by chemical means
Compound – a pure substance that can be broken down
into simpler substances by chemical means
Fe + O2  Fe2O3 (a synthesis reaction is when two pure
substances are chemically combined to form a
compound)
H2O  H2 + O2 (a decomposition reaction is when a
compound is separated into smaller pure substances)
Mixture – matter that has variable composition
KoolAid is a mixture it can be sweeter, more watery,
stronger tasting, etc.
Pure Substance – matter that always has the same
composition; pure water is always H2O. Water is
typically a mixture, especially tap water. Tap water
contains many chemicals. Some added to make the water
healthier and some trace elements that are too expensive
to remove.
A mixture can be separated into two or more pure
substances by physical means.
Homogeneous mixture – called a solution, does not vary
in composition from one region to another. Pepsi is an
example of a homogeneous mixture. Every drink you get
from the bottle is the same. One isn’t sweeter, or more
cola tasting.
Heterogeneous mixture – contains regions that have
different properties from one another. Examples range
from trail mix to Italian salad dressing. Whenever you
can isolate different samples from the mixture you are
dealing with a heterogeneous mixture.
Separation of Mixtures
Distillation is used to separate the pure substances from a
homogeneous mixture. Distillation takes advantage of
the physical property, boiling point.
Filtration is used to separate the components of a
heterogeneous mixture. Filtration takes advantage of
particle size.
Energy, Temperature, and Heat
Energy is the capacity to do work.
Heat is the flow of energy due to a temperature
difference.
Exothermic – energy exits the system to the surroundings
(the surroundings get hotter)
Endothermic – energy enters the system from the
surroundings (the surroundings get cooler)
Tfinal = T(hot) + T(cold)
2
Calculating Energy Changes
𝑸 = 𝒎𝒄∆𝑻
𝑸 = energy
𝒎 = mass
𝒄 = the specific heat capacity for the sample of matter
∆𝑻 = change in temperature = Tfinal – Tinitial
Here are the units associated with the variables above:
energy  joules (J)
mass  grams
the specific heat capacity  J/g-°C
change in temperature  °C
A. The specific heat capacity for water is 4.184 J/g°C. How much energy would be required to raise the
temperature of 255.8 g of water from 20.0°C to
77.6°C?
𝑸 = 𝒎𝒄∆𝑻
𝑸 = 255.8 g (4.184 J/g-°C) (77.6°C – 20.0°C)
𝑸 = 255.8 g (4.184 J/g-°C) (57.6°C)
𝑸 = 61600 J
The specific heat capacity is the amount of energy required
to raise the temperature of one gram of a substance by
one degree Celsius.
4.184 joules = 1 calorie
(a calorie is bigger than a joule)
I eat about 3,000,000 calories. That is 3000 kilocalories.
Nutritional calories are really kilocalories. On a food label
they will always be listed as a capital C as in 100 Cal. That
really means 100000 calories. A can of Pepsi has 100000
calories!!!
B. A 43.75 g sample of aluminum is heated by adding
5.58 X 103 J. The initial temperature of the aluminum
was 22.8°C what was the final temperature of the
aluminum?(See page 70 for 𝒄Al)
EOCQ’s
p.75
7,9,10,11,16, 17, 19, 27-31,34,35,38,39,41,43,44,55,59,61
Lab Experiments
1. Filtration/Distillation
2. Specific Heat Virtual Lab