1. CH. 2 CHEMISTRY

2. Reading quiz
Number your paper #1-10

3. Chapter 2 Matter and Energy
2.1
Classification of Matter

4. Matter Matter is the material that makes up all things
is anything that has mass and occupies space

5. Pure Substances A pure substance is classified as
a type of matter with a fixed or definite composition
an element that is composed of one type of atom
a compound that is composed of two or more elements always combined in the same proportion

6. Elements
Elements
are pure substances that contain only one type of material
include
copper, Cu
lead, Pb
aluminum, Al
The element copper consists of copper atoms.

7. Compounds
A compound
contains two or more elements in a definite ratio, such as
hydrogen peroxide (H2O2)
table salt (NaCl)
sugar (C12H22O11)
water (H2O)

8. Elements in a Compound
“Table salt” is a compound that contains the elements sodium and chlorine.
The decomposition of salt, NaCl, produces the elements sodium and chlorine.

9. Mixtures A mixture is a type of matter that consists of
two or more substances that are physically mixed but not chemically combined
two or more substances in different proportions
substances that can be separated by physical methods
A mixture of a liquid and a solid is separated by filtration.

10. Homogeneous Mixtures In a homogeneous mixture,
the composition is uniform throughout
the different parts of the mixture are not visible
Brass is a homogeneous mixture of copper and zinc atoms.

11. Scuba Breathing Mixtures
Breathing mixtures for scuba
are homogeneous mixtures. Some
examples are
Nitrox (oxygen and nitrogen gases)
Heliox (oxygen and helium gases)
Trimix (oxygen, helium, and nitrogen gases)
A Nitrox mixture is used to fill scuba tanks.

12. Heterogeneous Mixtures
In a heterogeneous mixture,
the composition varies from one part of the mixture to another
the different parts of the mixture are visible
Oil and water form a heterogeneous
mixture.

13. Classification of Matter

14. Learning Check
Identify each of the following as a pure substance or a mixture: A. pasta and tomato sauce B. aluminum foil C. helium D. air

15. Solution
Identify each of the following as a pure substance or a mixture: A. pasta and tomato sauce mixture B. aluminum foil pure substance C. helium pure substance D. air mixture

16. Learning Check Identify each of the following as a homogeneous or
heterogeneous mixture:
A. hot fudge sundae
B. shampoo
C. sugar water
D. peach pie

17. Solution
Identify each of the following as a homogeneous or heterogeneous mixture: A. hot fudge sundae heterogeneous mixture B. shampoo homogeneous mixture C. sugar water homogeneous mixture D. peach pie heterogeneous mixture

18. Chapter 2 Matter and Energy
2.2
States and Properties of Matter

19. Properties of Matter
Matter has characteristics called physical and chemical properties.

20. Solids Solids have a definite shape a definite volume
particles that are close together in a fixed arrangement
particles that move very slowly
Amethyst, a solid, is a purple form of quartz (SiO2).

21. Liquids Liquids have an indefinite shape, but a definite volume
the same shape as their container
particles that are close together, but mobile
particles that move slowly
A liquid has a definite volume, but takes the shape of its container.

22. Gases Gases have an indefinite shape an indefinite volume
the same shape and volume as their container
particles that are far apart
particles that move very fast
A gas takes the shape and volume of its container.

23. Summary of the States of Matter

24. Physical Properties Physical properties
are characteristics observed or measured without changing the identify of a substance
include shape, physical state, boiling and freezing points, density, and color of that substance

25. Physical Properties of Copper
Copper has these physical properties:
reddish-orange color
shiny
excellent conductor of heat and electricity
solid at 25 C
melting point 1083 C
boiling point 2567 C
Copper, used in cookware, is a good conductor of heat.

26. Physical Change A physical change occurs in a substance if there is
a change in the state
a change in the physical shape
no change in the identity and composition of the substance
In a physical change, a gold ingot is hammered to form gold leaf.

27. Examples of Physical Changes
paper torn into little pieces (change of size)
gold hammered into thin sheets of gold leaf (change of shape)
water poured into a glass (change of shape)
Water as a liquid takes the shape of its container.

28. Chemical Properties and Changes
Chemical properties describe the ability of a substance
to interact with other substances
to change into a new substance
When a chemical change takes place, the original substance is turned into one or more new substances with new chemical and physical properties.

29. Chemical Change
During a chemical change, a new substance forms that has
a new composition
new chemical properties
new physical properties
Sugar caramelizing at a high temperature is an example of a chemical change.

30. Some Chemical Changes
Silver tarnishes Shiny metal reacts to form a black, grainy coating. Wood burns A piece of wood burns with a bright flame to form ash, carbon dioxide, water vapor, and heat. Iron rusts A shiny nail combines with oxygen to form orange-red rust.

31. Energy Energy makes objects move makes things stop
is needed to “do work”
When water flows from the top of a dam, potential energy is converted to
kinetic energy.

32. Work Work is done when you climb you lift a bag of groceries
you ride a bicycle
you breathe
your heart pumps blood
water goes over a dam
At the top of the rock, a climber has more potential energy than when she started the climb.

33. Potential Energy Potential energy is energy
stored for use at a later time.
Examples are
water behind a dam
a compressed spring
chemical bonds in gasoline, coal, or food
Diesel fuel reacts in a car engine to produce energy.

34. Kinetic Energy Kinetic energy is the energy of matter in motion.
Examples are
swimming
water flowing over a dam
working out
burning gasoline
When water flows from the top of a dam, potential energy is converted to kinetic energy.

35. Learning Check
Identify the energy in each example as potential or kinetic: A. rollerblading B. a peanut butter and jelly sandwich C. mowing the lawn D. gasoline in the gas tank

36. Solution
Identify the energy in each example as potential or kinetic: A. rollerblading (kinetic) B. a peanut butter and jelly sandwich (potential) C. mowing the lawn (kinetic) D. gasoline in the gas tank (potential)

37. Units for Measuring Energy or Heat
Heat is measured in joules or calories. The SI unit of energy
is the joule (J). The unit calorie is the amount of energy
needed to raise the temperature of 1 g of water by 1 C.
4.184 joules (J) = 1 calorie (cal)
1 kJ = 1000 J
1 kilocalorie (kcal) = 1000 calories (cal)

38. Examples of Energy in Joules

39. Learning Check
How many cal are obtained from a pat of butter if it provides 150 J of energy when metabolized? A cal B. 36 cal C. 630 cal

40. Solution
How many cal are obtained from a pat of butter if it provides 150 J of energy when metabolized? Step 1 State given and needed quantities. Given: 150 J Need: calories Step 2 Plan: J cal Step 3 Equalities/Conversion factor 1 calorie = J 1 cal and J J 1 cal Step 4 Set up problem. 150 J x 1 cal = 36 cal The answer is B J

41. Sample Problem 2.3 Energy Units
When 1.0 g of diesel burns in an diesel car engine, 48,000 J are released. What is this quantity of energy in calories?
Solution
Step 1 Given 48,000 J Need calories (cal)
Step 2 Plan
Step 3 Equalities/Conversion Factors
Step Set Up Problem
Study Check 2.3
The burning of 1.0 g of coal produces 8.4 kcal. How many joules are produced?
Two SFs Exact Two SFs

42. Chapter 2 Matter and Energy
2.4
Temperature

43. Temperature Temperature
is a measure of how hot or cold an object is compared to another object
indicates the heat flow from the object with a higher temperature to the object with a lower temperature
is measured using a thermometer

44. Temperature Scales The temperature scales
are Fahrenheit, Celsius, and Kelvin
have reference points for the boiling and freezing points of water
A comparison of the Fahrenheit, Celsius, and Kelvin temperature scales between the freezing and boiling points of water.

45. Learning Check
A. What is the temperature at which water freezes? 1) 0 F 2) 0 C 3) 0 K B. What is the temperature at which water boils? 1) 100 F 2) 32 F 3) 373 K C. How many Celsius units are between the boiling and freezing points of water? 1) 100 2) 180 3) 273

46. Solution
A. What is the temperature at which water freezes? 2) 0 C B. What is the temperature at which water boils? 3) 373 K C. How many Celsius units are between the boiling and freezing points of water? 1) 100

47. Fahrenheit – Celsius Formula
On the Fahrenheit scale, there are 180 F between the freezing and boiling points; on the Celsius scale there are 100 C.
180 F = 9 F = 1.8 F
100 C 5 C C
In the formula for calculating the Fahrenheit temperature, adding 32 adjusts the zero point of water from 0 C to 32 F.
TF = 1.8TC

48. Temperature Math: Converting oC to oF
The temperature equation involves the exact numbers 1.8 and 32. Only the temperature is measured. To convert C to F, a multiplication rule is followed by an addition rule. Multiplication step 1.8(–10. C) = –18 F (2 SFs) Addition step – 18 F ones place + 32 exact = 14 F ones place

49. Solving a Temperature Problem
Hypothermia may occur when body temperature drops below 35 C (95 F).
A person with hypothermia has a body temperature of 34.8 C. What is that temperature in F?

50. Solving a Temperature Problem
A person with hypothermia has a body temperature of 34.8 C. What is that temperature in  F?
Step 1 State given and needed quantities.
Given: 34.8 C Need: TF
Step 2 Plan: TC TF
Step 3 Equality/Conversion factor TF = 1.8TC
Step 4 Set up problem.
TF = 1.8(34.8 C) + 32
exact 3 SFs exact
= = 94.6 F one decimal place

51. Converting Fahrenheit to Celsius
TC is obtained by rearranging the equation for TF.
TF = TC
Subtract 32 from both sides
TF – = 1.8TC + (32 – 32)
TF – = 1.8TC
Divide by 1.8 = TF – = 1.8TC
TF – 32 = TC
1.8

52. Learning Check
The normal body temperature of a chickadee is F. What is that temperature on the Celsius scale?
A C
B C
C C

53. Solution
Step 1 State given and needed quantities. Given: F Need: TC Step 2 Plan: TF TC Step 3 Equality/Conversion factor TC = (TF – 32) 1.8 Step 4 Set up problem. = (105.8 – 32 ) (32 and 1.8 are exact) = 73.8 F = 41.0 C The answer is C. 1.8 (exact) 3SFs 3 SFs

54. Kelvin Temperature Scale
The Kelvin temperature
scale has 100 units between the freezing and boiling points of water
100 K = 100 C or 1 K = 1 C
is obtained by adding 273 to the Celsius temperature
TK = TC
has the lowest possible temperature, absolute zero, at 0 K
0 K = –273 C

55. Temperatures

56. Learning Check What is normal body temperature of 37 C in Kelvin?
A. 236 K
B. 310 K
C. 342 K

57. Solution What is normal body temperature of 37 C in Kelvin?
Step 1 State given and needed quantities.
Given: 37 C Need: TK
Step 2 Plan: TC TK
Step 3 Equality/Conversion factor
TK = TC
Step 4 Set up problem.
TK = 37 C
= K (to ones place) Answer is B.

58. Sample Problem 2.4 Converting Celsius to Fahrenheit
A room is heated to 22 C. If that temperature is lowered by 1 C, it can save as much as 5% in energy costs. What temperature, in Fahrenheit degrees, should be set to lower the temperature by 1 C?
Solution
Step 1 Given 22 C - 1 C = 21 C Need TF
Step 2 Plan
Step 3 Equalities/Conversion Factors
Step Set Up Problem Substitute the Celsius temperature into the equation and solve.
In the equation, the values of 1.8 and 32 are exact numbers, which do not affect the number of SFs.
Study Check 2.4
In the process of making ice cream, rock salt is added to crushed ice to chill the ice cream mixture. If the
temperature drops to -11 C, what is it in Fahrenheit degrees?
TF = 1.8(TC) + 32
TF = 1.8(21) + 32
Two SFs Exact
TF =
1.8 is exact; 32 is exact
= 70. F Answer to the ones place

59. Sample Problem 2.5 Converting Fahrenheit to Celsius
In a type of cancer treatment called thermotherapy, temperatures as high as 113 F are used to destroy cancer cells. What is that temperature in degrees Celsius?
Solution
Step 1 Given 113 F Need TC
Step 2 Plan
Step 3 Equalities/Conversion Factors
Step Set Up Problem Substitute the Fahrenheit temperature into the equation and solve.
Study Check 2.5
A child has a temperature of F. What is this temperature on a Celsius thermometer?

60. Sample Problem 2.6 Converting Celsius to Kelvin Temperature
A dermatologist may use liquid cryogenic nitrogen at -196 C to remove skin lesions and some skin cancers. What is the temperature of the liquid nitrogen in kelvins?
Solution
Step 1 Given -196 C Need TK
Step 2 Plan
Step 3 Equalities/Conversion Factors
Step Set Up Problem Substitute the Fahrenheit temperature into the equation and solve.
Study Check 2.6
On the planet Mercury, the average night temperature is 13 K, and the average day temperature is 683 K.
What are these temperatures in degrees Celsius?
TK = TC + 273
TK = TC + 273
TK =
= 77 K Answer to the ones place

61. Chapter 2 Matter and Energy
2.6
Energy and Nutrition

62. Calorimeters A calorimeter is used to measure heat transfer
consists of a steel container filled with oxygen and a measured amount of water
indicates the heat gained by water, which is the heat lost by a sample during combustion
In a calorimeter, the burning of a food sample increases the temperature of water, which is used to calculate the energy value of the food.

63. Energy and Nutrition
On food labels, energy is shown as the nutritional
Calorie, written with a capital C. In countries other
than the United States, energy is shown in kilojoules (kJ).
1 Cal = calories
1 Cal = 1 kcal

64. Caloric Food Values The caloric or energy value for 1 g of a food
is given in kilojoules (kJ)
or kilocalories (kcal).

65. Energy Values for Some Foods

66. Energy Requirements
The amount of energy needed by a human each day depends on
age (see Table 2.10)
gender
physical activity (see Table 2.11)

67. Learning Check
A cup of whole milk contains 13 g of carbohydrate, 9.0 g of fat, and 9.0 g of protein. How many kilocalories does a cup of milk contain? (Round final answer to the tens place.) A. 50 kcal B. 80 kcal C. 170 kcal

68. Solution 13 g carbohydrates x 4 kcal/g = 52 kcal
A cup of whole milk contains 13 g of carbohydrate, 9.0 g of fat, and 9.0 g of protein. How many kilocalories does a cup of milk contain? (Round final answer to the tens place.)
13 g carbohydrates x 4 kcal/g = 52 kcal
9.0 g fat x 9 kcal/g = 81 kcal
9.0 g protein x 4 kcal/g = 36 kcal
169 kcal
Rounds off to 170 kcal (tens place)
Answer is C.

69. Sample Problem 2.8 Caloric Content for a Food
At a fast-food restaurant, a hamburger contains 37 g of carbohydrate, 19 g of fat, and 24 g of protein. What is the total energy content in kilocalories? Round off the kilocalories for each type of food to the tens place.
Solution
Using the energy values for carbohydrate, fat, and protein (see Table 2.8), we can
calculate the kilocalories for each type of food and the total kcal:
Study Check 2.6
If you buy the same hamburger as in Sample Problem 2.8 at a fast-food restaurant in Canada, what is the energy
content stated in kilojoules? Round off the kilojoules for each food type to the tens place.

70. Chapter 2 Matter and Energy
2.7
Changes of State
When a gram of steam condenses, 2260 J are released.

71. Melting and Freezing A substance
is melting while it changes from a solid to a liquid
is freezing while it changes from a liquid to a solid
such as water has a freezing (melting) point of 0 C
A solid requires heat to change to a liquid; a liquid gives off heat to change to a solid.

72. Evaporation and Condensation
Water
evaporates when molecules on the surface gain sufficient energy to form a gas.
condenses when gas molecules lose energy and form a liquid.
During evaporation, molecules of the liquid are converted to gas at the surface of the liquid.

73. Boiling of Water When water is boiling,
all the water molecules acquire enough energy to form a gas (vaporize)
bubbles of water vapor appear throughout the liquid
During boiling, molecules of the liquid are converted to gas throughout the liquid as well as at the surface.

74. Sublimation Sublimation occurs when a solid changes directly to a gas
is typical of dry ice, which sublimes at −78 C
takes place in frost-free refrigerators
is used to prepare freeze-dried foods for long-term storage
Heat of Sublimation (water)
620. cal or cal
1 g H2O g H2O
Dry ice sublimes at –78 °C.

75. Summary of Changes of State
A solid melts to form a liquid and sublimes to form a gas; a liquid boils to form a gas and freezes to form a solid; a gas condenses to form a liquid and undergoes deposition to form a solid.