Object 2
Object 1
Physics and chemistry
Unit 2: Matter
Unit 2. Matter
Index
1. States of matter................................................................................................................2
1.1.- The kinetic molecular model......................................................................................2
2. Graphs of change of state................................................................................................5
3. Gas laws..........................................................................................................................7
2.1 Boyle's Law: The Pressure-Volume Law.................................................................7
2.2 Charles' Law: The Temperature-Volume Law..........................................................8
Remember: Temperature has to be in Kelvin........................................................8
2.3 Gay-Lussac's Law: The Pressure Temperature Law................................................8
Remember: Temperature has to be in Kelvin........................................................8
4. Classification of matter.................................................................................................10
4.1.- Separation of mixtures.........................................................................................10
1.- Filtration.............................................................................................................10
2.- Decanting............................................................................................................10
3.- Crystallization....................................................................................................10
4.- Distillation..........................................................................................................11
5.- Magnetic separation............................................................................................11
6.- Chromatography.................................................................................................11
5. Solution.........................................................................................................................11
5.1. What is it?.............................................................................................................11
5.2. Components of a binary solution :.........................................................................11
5.3. Types of solutions:.................................................................................................11
5.4. Process of solution.................................................................................................11
5.5. Factors affecting solubility....................................................................................12
5.6. Factors affecting the dissolution rate.....................................................................12
Activities...........................................................................................................................12
Practice exam....................................................................................................................14
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Physics and chemistry
Unit 2: Matter
1. States of matter
1.- What are the three states of matter?
2.- Complete:
solid
liquid
gas
mass
¿constant or
variable?
¿constant or
variable?
¿constant or
variable?
High or low?
Yes or no?
Yes or no?
volume
shape
density
Can be mixed?
Can be
compressed?
1.1.- The kinetic molecular model
– All matter is made up of tiny particles
– The particles within matter are in constant motion
– Temperature affects the speed of particles. Higher temperature means higher
speed
– There are forces which attract the particles. Closer particles mean stronger forces.
3.- Graphical representation of particles in solid, liquid and gas
4- Name the six changes of state
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Physics and chemistry
solid
Unit 2: Matter
liquid
How are these changes of state?
1.- Solid to liquid
Draw
gas
This change is called: fusion or melting
The temperature at which this happens is
called: melting point
Explanation
When we heat a solid, its particles have
more mobility. If we heat it enough until
the forces of atracction among the
particles are weak enough, then a change
of state is produced
2.- Liquid to solid
Draw
Tn this change of state, we need to
increase temperature
This change is called:
The temperature at which this happens is
called:
Explanation
3.- Liquid to gas
Draw
Tn this change of state, we need to
temperature
This change is called:
The temperature at which this happens is
called: boiling point
Tn this change of state, we need to
temperature
Explanation
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Physics and chemistry
4. Gas to liquid
Draw
Unit 2: Matter
This change is called:
The temperature at which this happens is
called: boiling point
Tn this change of state, we need to
temperature
Explanation
5.- Solid to gas
Draw
This change is called:
Tn this change of state, we need to
temperature
Explanation
6.- Gas to solid
Draw
This change is called:
Tn this change of state, we need to
temperature
Explanation
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Physics and chemistry
Unit 2: Matter
2. Graphs of change of state
Activities
1. A sample of water is heated from a liquid at 40oC to a gas at 110oC.
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Physics and chemistry
Unit 2: Matter
a) On the heating curve diagram provided above, label each of the following
regions:
Liquid, only ; Gas, only; Phase change
b) For section QR of the graph, state what is happening to the water molecules as
heat is added.
c) For section RS of the graph, state what is happening to the water molecules as
heat is added.
2. The graph below represents the heating curve of a substance that starts as a solid
below its freezing point.
What is the melting point of this substance? (1) 30oC (2) 55oC (3) 90oC (4) 120oC
3. The graph below represents a substance that starts as a liquid. What type of graph is
this, heating curve or cooling curve? What is the melting point? So what substance is it?
4. The graph below represents a substance that starts as a liquid.What type of graph is
this, heating curve or cooling curve? What is the boling point? At 60º C the state of this
substance is.... and at 80 º C............................
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Physics and chemistry
Unit 2: Matter
3. Gas laws
One of the most amazing things about gases is that, despite wide differences in chemical
properties, all the gases more or less obey the gas laws. The gas laws deal with how
gases behave with respect to pressure, volume, temperature, and amount.
Gases are the only state of matter that can be compressed very tightly or expanded to fill
a very large space. Pressure is force per unit area, calculated by dividing the force by
the area on which the force acts.
The units of pressure that are used are pascal (Pa), standard atmosphere (atm), and torr.
1 atm is the average pressure at sea level. It is normally used as a standard unit of
pressure. The SI unit though, is the pascal. 101,325 pascals equals 1 atm.
Volume is the quantity of three-dimensional space occupied by a liquid, solid, or gas.
Common units used to express volume include liters or cubic meters,
Temperature is a measure of the average kinetic energy of the particles in a sample of
matter, expressed in terms of units or degrees designated on a standard scale.
Instrument of measurement: Thermometer and the unit in the SI is Kelvin
The Kelvin temperature scale is the standard metric system of temperature measurement
and perhaps the most widely used temperature scale used among scientists. The Kelvin
temperature scale is similar to the Celsius temperature scale in the sense that there are
100 equal degree increments between the normal freezing point and the normal boiling
point of water. However, the zero-degree mark on the Kelvin temperature scale is 273.15
units cooler than it is on the Celsius scale. So a temperature of 0 Kelvin is equivalent to a
temperature of -273.15 °C. Observe that the degree symbol is not used with this system.
For example, a temperature of 300 Kelvin, such a temperature is abbreviated as 300 K.
Conversions between Celsius temperatures and Kelvin temperatures (and vice versa) can
be performed using one of the two equations below.
T°C = T K - 273.15°
TK = T°C + 273.15
2.1 Boyle's Law: The Pressure-Volume Law
Robert Boyle (1627-1691)
Boyle's law or the pressure-volume law states that the volume of a given amount of gas
held at constant temperature varies inversely with the applied pressure when the
temperature and mass are constant.
When pressure goes up, volume goes down. When volume goes up, pressure goes down.
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Physics and chemistry
Unit 2: Matter
P1V1 = P2V2
This equation states that the product of the initial volume and pressure is equal to the
product of the volume and pressure after a change in one of them under constant
temperature.
For example, if the initial volume was 500 mL at a pressure of 760 atm, when the
volume is compressed to 450 mL, what is the pressure?
Plug in the values:
P1V1 = P2V2
(760 atm)(500 mL) = P2(450 mL)
760 x 500 /450 = P2
844 atm = P2
The pressure is 844 atm after compression.
2.2 Charles' Law: The Temperature-Volume Law
Jacques Charles (1746 - 1823)
This law states that the volume of a given amount of gas held at constant pressure is
directly proportional to the Kelvin temperature.
As the volume goes up, the temperature also goes up, and vice-versa.
Also same as before, initial and final volumes and temperatures under constant pressure
can be calculated.
V1 / T1 = V2 / T2
Remember: Temperature has to be in Kelvin
2.3 Gay-Lussac's Law: The Pressure Temperature Law
Joseph Gay-Lussac (1778-1850)
This law states that the pressure of a given amount of gas held at constant volume is
directly proportional to the Kelvin temperature.
As the pressure goes up, the temperature also goes up, and vice-versa.
Also same as before, initial and final volumes and temperatures under constant pressure
can be calculated.
P1 / T1 = P2 / T2
Remember: Temperature has to be in Kelvin
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Physics and chemistry
Unit 2: Matter
Activities:
5.- A sample of helium has a volume of 3 liters when the pressure is 500 torr. What
volume does the gas occupy at 300 torr?
Sol. 5 L
6. At a pressure of 100 kPa, a sample of a gas has a volume of 50 liters. What pressure
does it exert when the gas is compressed to 40 liters?
Answer: 125 kPa
7. When a 375 mL sample of nitrogen is kept at constant temperature, it has a pressure of
1.2 atmospheres. What pressure does it exert when compressed to 125 mL?
Answer: 3.6 atm
8. When a sample of hydrogen is compressed to 200 mL, its pressure changes from 0.4
atmospheres to 1.2 atmospheres. What was the original volume of the sample?
Answer: 600 mL
9. At constant pressure, a sample of gas occupies 420 mL at 210 K. What volume does
the gas occupy at 250 K?
Answer: 500 mL
10. A sample of argon gas has a volume of 6 liters at a temperature of 7 °C. What volume
does the gas occupy at 147 °C?
Answer: 9 L
11. At what Kelvin temperature will a sample of gas occupy 12 liters if the same sample
occupies 8 liters at 27 °C?
Answer: 450 K
12.A chemist produces 460 mL of oxygen gas at - 43 °C and constant pressure. To what
Celsius temperature must the oxygen be warmed in order for it to have a volume of 600
mL?
Answer: 27 °C
13. A sample of neon gas exerts a pressure of 120 kPa when the temperature is 400 K.
What pressure is produced when the temperature is raised to 600 K?
Answer: 180 kPa
14. A 400 mL sample of nitrogen in a sealed, inflexible container has a pressure of 1200
torr at a temperature of 250 K. It is known that the container will rupture at a pressure of
1800 torr. At what temperature will the container rupture?
Answer: 375 K
15. A sample of argon gas exerts a pressure of 180 kPa when the temperature is 23 °C .
What pressure is produced when the temperature is raised to 145 °C ?
Answer: 254.2 kPa
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Physics and chemistry
Unit 2: Matter
4. Classification of matter
mixtures
components are in variable
proportions
the separation of
components is done by
physical methods
matter
pure substances
components are in fixed
proportions
The separation of
components is done by
chemical methods (in the
case of compounds)
Homogeneus mixture
We cannot differentiate
between the components
Air, sea water
or steel
heterogeneus mixture
We can differentiate
between the components
of the mixture
granite
Compounds
formed by different
atoms, always combined
in fixed proportions
represented by formulas
Water
ammonia
glucose
Elements
Iron
They cannot be broken
oxygen
down into more simple
silver
substances
They are formed by atoms
of a single type
4.1.- Separation of mixtures
1.- Filtration
This is used to separate a solid from a liquid in which it does not dissolve, like sand and
water.
2.- Decanting
This is used for separating liquids of different densities, such as the mixture of water and
oil. The densest fluid is deposited at the bottom of the receptacle
3.- Crystallization
This method can be used to separate components of a solution. The liquid evaporates
and the solid remains at the bottom of the receptacle, forming crystals.
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Physics and chemistry
Unit 2: Matter
4.- Distillation
This is used for separating liquids of different boiling point, such as the mixture of water
and alcohol.
5.- Magnetic separation
The magnetic properties of some materials are used to separate them from other
materials. It is used, for example, to separate metals from rubbish.
6.- Chromatography
This is used to separate organic compounds depending on their affinity for a stationary
phase
5. Solution
5.1. What is it?
It is a homogeneus mixture with variable composition.
5.2. Components of a binary solution :
Solute: component in lower quantity
solvent: component in higher quantity
5.3. Types of solutions:
type
solute
solvent
solid
Solid solution
liquid
bronze
solid
gas
Gas solution
liquid
Wet clay
Hydrogen in
paladium
solid
Liquid solution
example
Sugar in water
liquid
Alcohol in water
gas
Fizzy drinks
solid
Dust in air
liquid
gas
gas
aerosol
air
5.4. Process of solution
When a solute and solvent are mixed, there is a maximum amount of solute that can be
dissolved in certain amount of solvent at a given temperature. This amount is called
solubility.
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Physics and chemistry
Unit 2: Matter
5.5. Factors affecting solubility
Pressure
 Gas in liquid . The higher the pressure, the higher the solubility
Temperature
 Gas in liquid. The higher the temperature, the lower the solubility
 solid in liquid. The higher the temperature, the higher the solubility
5.6. Factors affecting the dissolution rate
Contact surface A larger contact surface means a higher dissolution rate
Agitation. Greater agitation means a greater dissolution rate.
Activities
16. Explain using molecular kinetic theory, the change of water from solid to liquid and
liquid to gas by increasing temperature.
17.Why does the mirror fog in winter when we shower with hot water?
18. Complete the kinetic molecular model:
Matter is formed by tiny
in constant
Higher temperature means
motion. There are forces between
particles. Closer particles mean
forces.
19.Write several examples of mixtures, indicating whether they are homogeneous or
heterogeneous mixture.
20. Brass is an alloy of copper and zinc and constitutes a homogeneous mixture.
Common salt consists of chlorine and sodium and is a compound. What is the difference?
21. What separation techniques are used in each of these laboratory tools:
crystallizer, filter paper, decanter, ordinary funnel
22. Classify the following substances in heterogeneous mixtures, homogeneous and pure
substances:
granite- salt water -tap water- distilled water – milk – salt – detergent – copper –
sugar – orange juice – diamond
23. Indicates which physical method is best suited to separate the components of these
mixtures:
a) separation of particles from water
b) waste water from gasoline
c) alcohol from wine
d) iron particles from dust
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Physics and chemistry
Unit 2: Matter
24. What methods of separation for mixtures are used in these processes?
a) The extraction of salt from salt flats
b) The removal of particles from used oil
c) The procurement of fuels from oil
d) The retention of the particles of dust and pollen in a mask
25.Design a procedure to separate the components of these mixtures by means of
physical methods:
a) water, gasoline and diesel
b) aluminum chips, water and ethanol
c) salt water and oil
26. Define and give an example of each.
element- pure substance – compound -heterogeneus mixture – homogeneus
mixture – matter
27.Why is pouring hot water into rivers harmful to fish?
28. Indicate the solute and solvent in the following solutions and what type of
solution it is:
a) 30 ml of alcohol in 100 ml of water
b) salt water
c) air (78% Nitrogen and 21 % oxygen)
d) 96 º alcohol kit
e) Bronze (85 % Cu, 15 % Sn)
29. Complete:
a) Increasing pressure causes a
in the solubility of a
gas in a liquid
b) Increasing temperature causes a
in the solubility of a
solid in a liquid
c) Increasing temperature causes a
in the solubility of a
gas in a liquid
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Physics and chemistry
Unit 2: Matter
Practice exam
1.- Write kinetic molecular theory and explain the change that occurs when a liquid
becomes a gas.
2.When a sample of hydrogen is compressed to 240 mL, its pressure changes from 0.8
atmospheres to 2 atmospheres. What was the original volume of the sample?
Answer: 600 mL
3. A chemist produces 300 mL of oxygen gas at - 34 °C and constant pressure. To what
Celsius temperature must the oxygen be warmed in order for it to have a volume of
450 mL?
Answer: 85.5 °C
4.What pressure will a gas sample exert at 300 K if the same sample has a pressure of 4
atmospheres at 120 K?
Answer: 10 atm
5.- What is involved in the process of distillation? What is involved in the process of
crystallization?
6.- Describe how you would separate the following mixtures:
a) iron filings and sugar
b) salt and water
c) oil and water
d) alcohol and wine
7.- Create a diagram that details the classification of matter, giving an example of each
thing.
8. a) On the heating curve diagram provided above, label each of the following regions:
Liquid, only ; Gas, only; Phase change
b) What is the boiling point? And the melting point?
9.- Give two examples of each solution
a) a gas in a liquid solvent
b) a gas in a solid solvent
c) a liquid in a gas solvent
10.- List the factors that influence solubility. Briefly explain each one.
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