Energy and States of Matter

1
Energy and States of Matter
2
Energy

• When particles collide, energy is transferred
  from one particle to another.
• Law of conservation of energy energy can be
  neither created nor destroyed it can only be
  converted from one form to the other.

3
Particle Diagram

• Draw particle diagrams of water molecules for
  solid, liquid, and gas.

Solid/Ice Liquid/Water Gas/Steam
http//www.fda.gov/Food/ResourcesForYou/Consumers/
ucm197586.htm
http//www.volusia.org/services/public-works/water
-resources-and-utilities/
http//teacouncil.net/make-the-perfect-cup-of-tea/
4
Particle Diagram
5
Particle Diagram
Solid Liquid Gas
http//www.patana.ac.th/secondary/science/anrophys
ics/unit5/commentary.htm
Motion/Kinetic Energy of Particles Force of
Attraction for the Same Substance
6
PhET Simulation

• PhET Simulation

7
Solids

• Physical properties used to describe solids
• Hardness
• Shape
• Malleable
• Ductile
• Density
• Elasticity

• Characteristics of solids
• Particles are very close together
• Strong attractive forces between particles
• Particles vibrate but do not move out of position
• Fixed shape
• Fixed volume

8
Liquids

• Physical properties used to describe liquids
• Viscosity (resistance to flow)
• Concentration
• Fluid (has the ability to flow)
• Density

• Characteristics of liquids
• Particles are close together
• Weak attractive forces between particles
• Particles slide past each other
• Takes the shape of the container
• Fixed volume
• compressible
• Cohesion (ex. water-water)
• Adhesion (ex. Water-leaf surface)

9
Gasses

• Properties
• Particles are far apart
• No attractive forces between particles
• Takes the shape of the container
• Particles spread out to fill the container
• Can be identified by burning splint test
• O2 gas causes the burning splint to re-light
• CO2 gas causes the burning splint to go out
  quietly (fire extinguisher)
• H2 gas causes a popping sound

10
Real-world application

• Why are air bags safer than liquid bags or
  solid bags?

http//www.superstock.com/stock-photos-images/1570
R-134389
11
Gasses as Diatomic Molecules

• There are seven elements (all gasses) whose atoms
  are not stable as individuals.
• These atoms will always bond with another atom.
• If no other type of atom is available, they bond
  with another atom of the same type. These are
  called DIATOMIC MOLECULES.
• They are H2, O2, F2, Br2, I2, N2, Cl2

12
Common Gases
Air is a mixture of gases Nitrogen (N2) Oxygen
(O2) Argon (Ar) Carbon dioxide (CO2) Hydrogen
(H2) Ammonia (NH3) Methane (CH4)
http//patti-isaacs.com/portfolio/
13
Gas has Mass

• At your station there are two balloons filled
  with different gases (balloon A balloon B).
• Make observations about the following variables
  in both balloons
• (1) Volume (is one balloon bigger, or are they
  about the same?)
• (2) Temperature
• (3) Pressure
• Hold balloons A B at shoulder height and
  release.
• What happens to each balloon?
• What can you conclude about the density of each
  balloon (remember, Dm/V) compared to the density
  of the gas in the room?
• Find the mass of balloons B C on the scale.
• Does gas have mass? Support your response with
  your observations.

14
Grahams law (of effusion)

• Effusion when a gas escapes through a tiny hole
  in its container
• States that the rate of effusion of a gas is
  inversely proportional to the square root of the
  gass (molar) mass.
• What you need to know lighter gases travel
  faster than heavier gases.
• The bottom (decimal) number on the periodic table
  is the mass.

15
Temperature

• Temperature measure of the average kinetic
  energy of each particle within an object.
• Gases at the same temperature have the same
  kinetic energy.
• Kinetic energy ½(mv2)

16
Thermal EquilibriumTwo physical systems are in
thermal equilibrium if no heat flows between them
when they are connected by a path permeable to
heat.

• The arrows represent the relative movement of the
  particles (circles).

17

• Temperature
• Kelvin scale sets 0 as the temperature at which
  no more energy can be removed from matter and all
  motion stops.
• absolute zero- 0 on Kelvin scale written as 0K
• No negative Kelvin temps
• For all gas law problems, the temp must be in
  Kelvin

18
Temperature

• K C 273

• Convert the following temperatures into Kelvin
• a. 43 oC
• b. 135 0C
• Convert the following temperatures into Celsius
• a. 340 K
• 30 K
• Hint c to k, add
• k to c, subtract

19
Kinetic Molecular Theory

1. Gases consist of tiny particles (atoms or
   molecules).
2. These particles are so small, compared with the
   distances between them that the volume (size) of
   the individual particles can be assumed to be
   negligible (zero).
3. The particles are in constant random motion,
   colliding with the walls of the container. These
   collisions with the walls cause the pressure
   exerted by the gas.
4. The particles are assumed to not attract nor
   repel each other.
5. The average kinetic energy of the gas particles
   is directly proportional to the Kelvin
   temperature of the gas.

20
Pressure
Measures the force of particles hitting the
container per unit area
Which has more pressure? Why?
A
B
http//www.wisegeek.com/what-is-a-pressure-gauge.h
tm
21
Pressure

• The metric unit for measuring pressure is
  ATMOSPHERE (atm).
• Other units for measuring pressure
• mm of Hg (millimeters of mercury) 760 mm Hg 1
  atm
• kPa (kilopascals) 101.3 kPa 1 atm
• psi (pounds per square inch) 14.7 psi 1 atm

22
How to convert between pressure units

• Convert 795 mm Hg into atmospheres.
• Identify conversion factor.
• 760 mm Hg 1 atm
• Set up a dimensional analysis problem
• a series of fractions
• First fraction is number you started with over 1
• Second fraction is the conversion factor
• Units you started with should go at bottom of
  second fraction
• 795 mm Hg 1atm_____
• 1 760 mm Hg
• Solve the problem and cancel units
• (795)(1) 795 1.05 atm
• (1)(760) 760

23
Pressure conversions guided practice

• 1. The air pressure for a certain tire is 109
  kPa. What is this pressure in atmospheres?

24
Pressure conversions independent practice

• 1. The air pressure inside a submarine is 0.62
  atm. What would be the height of a column of
  mercury balanced by this pressure?
• 2. The weather news gives the atmospheric
  pressure as 1.07 atm. What is this atmospheric
  pressure in mm Hg?
• 3. An experiment at Sandia National Labs in New
  Mexico is performed at 758.7 mm Hg. What is this
  pressure in atm?
• 4. A bag of potato chips is sealed in a factory
  near sea level. The atmospheric pressure at the
  factory is 761.3 mm Hg. The pressure inside the
  bag is the same. What is the pressure inside the
  bag of potato chips in kPa?
• 10 minutes

25
Atmospheric pressure

• Atmospheric pressure is the result of collisions
  of air molecules with objects.
• Atmospheric pressure decreases with an increase
  in altitude. The air around the earth thins out
  at higher elevations.

(www.naval-technology.com)
(ghccprimetimers.org)
Which has more pressure exerted on it?
26
Atmospheric Pressure decreases with increasing
altitude.
(hendrix2.uoregon.edu)
1 atmosphere is defined as the air pressure at
sea level.
27
Measuring air pressure

• Barometers

• Manometers

• used to measure atmospheric pressure (weather
  reports)

• used to measure the pressure of other gases as
  compared to atmospheric pressure

28
STPStandard Temperature and Pressure
1 atm
OC
29
Relationships

• Direct Relationship when changing one variable
  causes the other variable to change in the same
  direction
• when one goes up, the other goes up when one
  goes down, the other goes down

30
Relationships

• Inverse Relationship when changing one variable
  causes the other variable to change in the
  opposite direction
• when one goes up,
• the other goes down
• Another word for inverse is indirect.

31
Boyles law

• Demo marshmallows and vacuum pump
• Independent variable_______________________
• Dependent variable ________________________
• Observations ____________________________________
  ________________________________________________
• Relationship ______________________________

32
Boyles Law

• Boyles Law states that gas pressure is inversely
  proportional to volume at constant temperature
  and number of particles of gases.
• Mathematical relationship
• P1V1 P2V2

This means pressure one times volume one
equals pressure two times volume two)
33
How does Boyles Law explain this?
(www.faculty.sdmiramar.edu) 

• A was balloon inflated in San Diego, CA and then
  taken to Denver, CO

34
Explain how these represent Boyles law?
A.
B.
syringe
Pressure gauge
ffden-2.phys.uaf.edu
(www.chemwiki.ucdavis.edu)
35
Boyles Law Example

• A gas has a volume of 100 ml when the pressure is
  1.4 atm. What is the volume, in mL, when the
  pressure is increased to 1.6 atm and the
  temperature is held constant?

36
If a gas has a volume of 100 ml when the
pressure is 1.4 atm, what is the volume, in mL,
when the pressure is increased to 1.6 atm and
the temperature is held constant?

• 1. List variables
• V1 100 mL
• P1 1.4 atm
• V2 ? mL
• P2 1.6 atm

• 2. Write formula
• P1V1 P2V2
• 3. Substitute in known values
• (100mL)(1.4atm) (V2)(1.6atm)
• 4. Rewrite without units.
• (100)(1.4) (V2)(1.6)
• If desired, switch the sides
• (V2)(1.6) (100)(1.4)
• If desired, switch the unknown and number
• (1.6)(V2) (100)(1.4)
• 5. Solve for unknown
• Combine terms
• (1.6)(V2) 140
• Isolate the variable
• (1.6)(V2) 140
• 1.6 1.6
• V2 87.5 mL

37
L-level Boyles Law Guided practice

• The volume of a quantity of a gas held at
  constant temperature and 1.00 atm of pressure is
  100. mL. What pressure does it take to reduce
  the volume to 95 mL?

38
K-level Boyles Law Guided Practice

• The pressure of a balloon is 101 kPa. What is the
  new pressure of a balloon after its volume is
  changed from 502 mL to 301 mL?

39
K-level Boyles Law Independent Practice

• A gas tank holds 2785 L of propane (C3H8) at 830.
  mm Hg. What is the volume of the propane at
  standard pressure?
• 2. A sample of neon (Ne) occupies a volume of
  85.0 mL at STP. What will be the volume of the
  neon when the pressure is reduced to 65.5 kPa?
• 3. 352 mL of chlorine (Cl2) under a pressure of
  680. mm Hg are transferred in a 450. ml
  container. The temperature remains constant at
  296 K. What is the pressure of the gas in the new
  container?
• 10 minutes

40
Charles law

• Demo balloons
• Independent variable_______________________
• Dependent variable ________________________
• Observations ____________________________________
  __________________________________________________
  ________________________________________
• Relationship ______________________________

41
Charles Law

• The volume of a given amount of gas varies
  directly to its kelvin temperature when pressure
  is constant.
• Mathematical relationship
• V1 V2
• T1 T2

This means volume one divided by temperature
one equals volume two divided by temperature two)
42
Charles Law
43
Charles Law
cfbt-us.com
44
Charles Law example

• A balloon inflated in an air conditioned room at
  27?C has a volume of 4.00 L. If it is heated to
  57?C and the pressure remains constant, what is
  the new volume?

45
A balloon inflated in an air conditioned room at
27?C has a volume of 4.00 L. If it is heated to
57?C and the pressure remains constant, what is
the new volume?

• 2. Write formula
• V1 V2
• T1 T2
• 3. Substitute in known values
• (4.00L) (V2)_
• (300K) (330K)
• 4. Rewrite without units
• (4.00) (V2)_
• (300) (330)
• Cross multiply
• (4.00)(330) (300)(V2)
• Combine terms
• 1320 (300)(V2)
• If desired, switch sides
• (300)(V2) 1320
• Isolate variable
• (300)(V2) 1320
• 300 300
• 5. Solve for unknown

• 1. List variables and
• Convert temp to Kelvin
• T1 27C 273 300 K
• V1 4.00 L
• T2 57C 273 330 K
• V2 ? L

46
L-level Charles law guided practice

• A gas kept at constant pressure has a volume of
  10.0 L at 25.0 C. At what Celsius temperature
  would the gas have a volume of 20.0 L?

47
K-level Charles law practice

• A container holds 50.0 mL of nitrogen at 25 C
  and a pressure of 736 mm Hg. What will be its
  volume if the temperature increases by 35 C?

48
Gay-Lussacs law

• Demo crush the can
• Independent variable_______________________
• Dependent variable ________________________
• Observations ____________________________________
  ________________________________________________
• Relationship ______________________________

49
Gay Lussacs Law

• The pressure of a gas varies directly to the
  Kelvin temperature of the sample, if the volume
  remains constant.
• Mathematical relationship
• P1 P2
• T1 T2

This means pressure one divided by temperature
one equals pressure two divided by temperature
two)
50
Gay-Lussacs law
51
Gay Lussacs Law
cfbt-us.com
52
Graph of Gay-Lussacs Law(direct relationship)
53
Gay-Lussacs Law example

• A gas in an aerosol can is at a pressure of 1.00
  atm and 27.0 oC. If the can is thrown into a
  fire, what is the internal pressure of the gas
  when the temperature reaches 927 oC?

54
A gas in an aerosol can is at a pressure of 1.00
atm and 27.0 oC. If the can is thrown into a
fire, what is the internal pressure of the gas
when the temperature reaches 927 oC?

• Write formula
• P1 P2
• T1 T2
• Substitute in known values
• (1.00atm) (P2)
• (300K) (1200K)
• Rewrite without units
• (1.00) (P2)
• (300) (1200)
• Cross-multiply
• (1.00)(1200) (300)(P2)
• Combine terms
• 1200 (300)(P2)
• If desired, switch sides
• (300)(P2) 1200
• Isolate variable
• (300)(P2) 1200
• 300 300
• Solve for unknown

• List variables
• Convert temp to Kelvin
• P1 1.00 atm
• T1 27C 273 300 K
• P2 ? atm
• T2 927C 273 1200 K

55
Gay- Lussacs law guided practice

• A sample of a gas has a pressure of 851 mm Hg at
  285C. To what Celsius temperature must the gas
  be heated to double its pressure if there is no
  change in the volume of the gas?

56
Real-world application

• Car tire pressure should be measured when the
  tires are warm after it has been driven. Why?

http//www.racintoday.com/archives/39412
57
Real-world application

• This tanker was steam cleaned on the inside, then
  closed. Why did it implode?

http//jmfs1.ortn.edu/myschool/DHundermark/jms8bsc
ience/index_testpage.html
58
Real-world application

• Why do aerosol cans have a warning to not
  incinerate them (put them in fire)?

http//www.sunlive.co.nz/news/26907-explosion-and-
fire-warning.html
59
K-level only Combined Gas Law

• Use when p, t, and v all change
• Temperature must be in Kelvin

60
Combined Gas Law practice

• A 25.0 ml balloon at 1.20 atm and 45oC, what is
  the temperature (in Celsius) of the gas when the
  volume changes to 100.0 mL and the pressure is
  0.816 atm?

61
A 25.0 ml balloon at 1.20 atm and 45oC, what
temperature would the gas be when the volume
changes to 100 mL and the pressure is 0.816 atm?

• 4. Substitute in known values
• (1.20atm)(25.0mL) (0.816atm)(100mL)
• (318K) (T2)
• 5. Rewrite without units
• (1.20)(25.0) (0.816)(100)
• (318) (T2)
• Combine terms
• 30 81.6
• 318 T2
• Cross multiply
• (30)(T2) (318)(81.6)
• Combine terms
• (30)(T2) 25948.8
• Isolate variable
• (30)(T2) 25948.8
• 30 30
• 6. Solve for unknown
• T2 865 K
• 6. Check to see if your answer makes sense

• 1. List variables
• 2. Convert temp to Kelvin
• V1 25.0 mL
• P1 1.20 atm
• T1 45C 273 318 K
• T2 ? K
• V2 100 ml
• P2 0.816 atm
• 3. Write formula
• P1V1 P2V2
• T1 T2

62
Combined gas law practice

• A sample of gas is stored in a 500.0 mL flask at
  1.07 atm and 10.0oC. The gas is transferred to a
  750.0 mL flask at 21.0oC. What is the new
  pressure in the flask?

63
IDEAL VS. REAL GASES

• Ideal gases dont really exist, but many gases do
  behave ideally under certain conditions (far
  apart and not able to attract each other).
• Ideal behavior occurs when the
• Pressure is ______________
• Temperature is __________
• Mass is ___________
• Volume is ____________
• Molecules are nonpolar.

64

• Which would act more ideally?
• He(g)
• H2O(g)
• Why?
• Does helium act more ideally at
• 800K
• 80K
• Why?
• Does helium act more ideally at
• 20.0 atm
• 1.00 atm
• Why?

65
Ideal Gas Law

• relates
• Pressure
• Volume
• Temperature
• number of moles(n)
• For a gas at STP, moles(n) and volume (v) are
  DIRECTLY related.
• 1 mole 22.4 L at STP
• This is called molar volume

We havent used this variable yet!
66
READ ONLY, DO NOT COPY!!!!!!

• For any ideal gas, the ratio VP is constant.
  
• nT
• We call this ratio R, the ideal gas constant.
• Using standard temp and pressure conditions, we
  can calculate the value of R.
• R (22.4L)(1atm)
• (1mol)(273K)
• R 0.0821 L atm/mole K
• Because of the units on R, P must be in atm, V
  must be in L, and T must be in K.
• Since R is a constant, we will never be solving
  for it. Rearrange
• R VP
• nT to PV nRT
• PV nRT (pronounced pivnert) is called the
  ideal gas law equation

67
Ideal Gas Law practice

• What volume would 1.41 moles of oxygen occupy at
  351K and 2.30 atm?

68
What volume would 1.41 moles of oxygen occupy
at 351K and 2.30 atm?

• 1. List variables
• 2. Convert temp to
• Kelvin
• V ?
• n 1.41 moles
• T 351 K
• P 2.30 atm
• R 0.0821 L atm/mol K

• 3. Write formula
• PV nRT
• 4. Substitute in known values
• (2.30atm)(V) (1.41mol)(0.0821Latm/molK)(351K)
• Rewrite with no units
• (2.30)(V) (1.41)(0.0821)(351)
• Combine terms
• 5. Solve for unknown Combine variables, then
  divide to get v by itself.
• V 17.7 L

69
Ideal gas law practice

• What temperature, in Celsius, would
• 6.00 moles of Helium occupy in a 25.0 L container
  at 1.26 atm?

70
Independent Practice (10 min)

• Calculate the pressure (in atm) of a 212 Liter
  tank containing 23.3 mol of argon gas at 25C?
• 2. At what temperature would 2.10 moles of N2
  gas have a pressure of 1.25 atm and in a 25.0 L
  tank?
• 3. What volume is occupied by 5.03 g of He at
  28C and a pressure of 0.998atm?
• 4. A 5000. L weather balloon contains 10.0 moles
  of He gas. What is the pressure (in atm) when the
  balloon rises to a point where the temperature is
  -10.0C and the gas has completely filled the
  balloon.

71
Avogadros Principle

• Equal volumes of gases at the same temperature
  and pressure contain the same number of
  molecules.
• The type of gas doesnt matter.
• V1 V2
• n1 n2

72
Avogadros principle example
  Relationship between n and V Increased number
of gas particles Increased number of collisions
with the walls of the container Increased total
force of collisions Inside pressure greater than
outside pressure Container expands
73
Avogadros Law

• At STP, one mole of a gas occupies a volume of
  22.4 L.
• 1.0 mol of gas
• or
• 6.02 x 1023 particles

22.4 L container
74
Which container has the most gas particles?
5 L 0.20 atm
C
B
3 L 0.5 atm
A
2 L 1 atm
All containers are at the same temperature.
75
Compare Properties of Three States of Water

• You have seen water in its three common states of
  matter before solid (ice), liquid (water), and
  gas (steam or water vapor). However, have you
  ever thought about how the water particles are
  changing between these three states? You will
  investigate the physical and chemical properties
  of water in its different states.
• For your observations of the shape and volume,
  they can be either definite or not definite.
• Observe the ice cubes in their beaker.
• Do the cubes have a definite shape or do they
  take the shape of their container?
• Do the cubes have a definite volume or can the
  ice be compressed?
• Observe the liquid water in its beaker.
• Do the water molecules have a definite shape or
  do they take the shape of their container?
• Do the water molecules have a definite volume or
  can they be compressed?
• Observe the beaker full of air. In Houston we
  have enough humidity that there are actually
  quite a lot of gaseous water molecules in that
  beaker.
• Do the water and air particles have a definite
  shape or do they take the shape of their
  container?
• Do the water and air particles have a definite
  volume or can they be compressed?

  Shape Volume Particle Diagram
  Ice (solid)        
  Water (liquid)        
  Air (gas)        
76
Compare the compressibility of the three states
of matter using syringes
Plunger ?
Compressibility tells scientists how close
together particles are to each other and how much
closer they can be squeezed together. You will
compare the relative amount of compressibility
for samples in different states of matter.

• Gently push in the plunger of the syringe
  containing sand.
• Gently push in the plunger of the syringe
  containing water.
• Gently push in the plunger of the syringe
  containing air.
• 1)Record your observations ranking the syringes
  as the most, middle, or least compressible
  samples.
• 2)When scientists discuss compressibility, they
  are determining how much closer together
  particles can get to each other. Based on this
  knowledge, infer whether the samples had the
  most, middle, or least space between the
  particles.
• 3)For the particle diagrams, sketch the end of
  the syringe containing the samples and how close
  together or far apart the particles are for each
  sample before being compressed by the plunger.

1 2 3
  Observed Compressibility Inferred Space Between Particles Particle Diagram
  Sand (solid)        
  Water (liquid)        
  Air (gas)        
77
Holey Bottle

• Cover the hole near the bottom of the bottle with
  your finger, then fill the bottle with water.
• Without removing your finger, tighten the cap on
  the water bottle.
• Make a prediction of what the water will do when
  the finger is removed from the hole.
• Remove your finger and observe the water in the
  bottle.
• Do your observations match your prediction?
• Twist the cap on and off the water bottle.
• How does the water react differently to the cap
  being on and off the bottle?
• Based on your knowledge of the air pressure
  inside and outside of the bottle, why doesnt the
  bottle leak when the cap is on?

78
Broken Straw?

• Fill the cup partially with water.
• A student will try to use two straws to drink the
  water simultaneously one straw inside the cup
  of water, the other outside the cup of water.
• Make a prediction about what will happen when the
  student tries to drink with both straws
  simultaneously.
• Have a student volunteer try to use both straws
  simultaneously to drink water out of the cup.
• Do your observations match your prediction?
• Based on your knowledge of the properties of
  gases and liquids, why does the student not drink
  any water?
• Throw the used straws in the trash.