2026-2027 Daniela Payne Chem 280 Midterm Study Guide: Chapters 1-9 & Homework Sets West
Coast University
CHAPTER 1-9 MIDTERM
CHAPTER 1
DEFINITIONS:
Chemistry: Chemistry is the science that tries to understand what matter does
by understanding what molecules do.
The science that studies the connections between the properties of matter and the
particles that compose that matter.
Scientific Method: makes use of observations, hypotheses, laws, theories, and
experiments.
Observation: When a given sample of gasoline is burned in a closed container, the mass of
the container and its contents does not change
involve measuring or observing some aspect of nature
Hypo: tentative interpretations of the observations.
Laws: A short statement that summarizes a large number of observations
Theories: models that explain and give the underlying causes for observations and laws
Atomic theory
Analytical vs Quantification: how much, makes how much involves measurement as
part of observation.
1g of H = 6.022x 10 ^23 atoms
QUESTIONS:
1. WHAT ARE THE STEPS IN SCIENTIFIC METHOD (overview):
2. Classify each statement: obs, hypo, laws, theories.
3. SCIENTIFIC THEORY: A gas is composed of small particles in constant motion.
4. WATER MOLECULE CONTAINS: 2 H + 1 oxygen.
5. AT ROOM TEMP WATER IS LIQUID BC: water repels each other AKA characteristics.
6. IS EVERYTHING CHEMICAL: T. IE] N2 78.1 %, 02 21 %, PENICAL(CARBON)
7. Mass equals reactions and products: chemical rxn we don’t loss any mass LAW of CONSERVATION
8. Where can you find chemicals? You can find chemicals in the hardware store, a chemical
stockroom, All around you and even inside of you
CHAPTER 2
DEFINITIONS:
Metric system vs SI units Mass kg kilogram, g grams
C > F > K * = temperature Time: Seconds: mins
Meter (m); length Volume: liters
,QUESTIONS:
1 m = 100cm > 1m ^3 =
[ 100 x 100 x100 ] =
1000,000 cm ^3
1 kg = 1000 g
454 g = 1 lb.
1 km = 1000 m
0.1 L = 1 dL
5983.0 move decimal to the left. =
5.9X10^-3 move decimal to the left
0.0059 move decimal to the right. =
5.9X10^3 move decimal to the right
2.705 mg > kg
10^-3mg > 1000kg = 10 ^-6
1g /1000 mg > 1kg / 1000 g
= 0.000002705 vs 2.705 x 10 ^-6
significant figures (digits): 0.010101
o (zeros to the right of a nonzero number) that fall after a
decimal point are significant.
o 005.10 03.00
o Trailing zeros that fall before a decimal point are significant.
o 50.00 1700.24
o 0.0005 has only one significant digit.
o 350= 3.5×102 to indicate two significant figures or as
3.50×102 to indicate three
Multiplication or division Addition or Subtraction
, D=m/v
1.2 KG / 33.1 CC (ml) > D = g/ml
1000g/ 1kg > 1.2x 10^2 /33.1 =
2 sf = 36
MATTER AND ENERGY
CHAPTER 3
• 3.2 Define Matter: anything that occupies space and has mass.
Atoms: building blocks of matter.
Molecules: two or more atoms joined
• 3.2 Classify matter as S > L > G characteristics and examples ** chart **
o Ice, diamond, quartz, and iron: solid matter
o crystalline solids include salt and diamond. – well ordered, 3D structure
o amorphous solids include glass, rubber, and plastic. – no long range order
o Water, gasoline, alcohol, and mercury: liquid matter
o Oxygen, helium, and carbon dioxide: gases.
Atomic/ Atomic/
Molecular Molecular
State Motion Spacing Volume Compressibility
Solid Oscillation/ Close: together Definite Definite Incompressible
about
fixed-point
Liquid Free to move Close; together Indefinite Definite Incompressible
another
Free to move Far apart Indefinite Indefinite compressible
relative to one
another
, • 3.3Classify matter as element , compound, or mixture define **
• Matter may be a pure substance, or it may be a
mixture.
• A pure substance may be either an element (Na,
H2 ) or a compound. Ie: water ionic vs NaCl
molecular)
• A mixture may be either homogeneous or
heterogeneous.
• Mixtures may be composed of two or more elements, two or more compounds (ie:H20), or a
combination of both.
• Compound: substance is composed of 2 or more elements in fixed, definite proportions.
• Element: pure substance that cannot be broken down into simpler substances.
3.4Distinguish between physical and chemical properties
• PP: doesn’t change composition: phase
change, boiling point of water, and boiling .
When water boils, it turns into a gas, but the
water molecules are the same in both the
liquid water and the gaseous steam.
• CP: changing its composition, chemical rxn:
The susceptibility of iron to rusting, and
rusting. When iron rusts, it turns from iron to iron(III) oxide.
• Substance changes it composition (the particles change from one type to another).
ANS:C P, P, P
• 3.5Distinguish between physical and chemical changes
• PP: matter changes its appearance but not its
composition. If you push the button on a lighter
without turning the flint, some of the liquid
butane vaporizes to gaseous butane. Since the
liquid butane and the gaseous butane are both
composed of butane molecules, this is a physical
change.
• CP: matter does change its composition.If you push the button and turn the flint to create a
spark, you produce a flame. The butane molecules react with oxygen molecules in air to form new
molecules, carbon dioxide and water. This is a chemical change.
Coast University
CHAPTER 1-9 MIDTERM
CHAPTER 1
DEFINITIONS:
Chemistry: Chemistry is the science that tries to understand what matter does
by understanding what molecules do.
The science that studies the connections between the properties of matter and the
particles that compose that matter.
Scientific Method: makes use of observations, hypotheses, laws, theories, and
experiments.
Observation: When a given sample of gasoline is burned in a closed container, the mass of
the container and its contents does not change
involve measuring or observing some aspect of nature
Hypo: tentative interpretations of the observations.
Laws: A short statement that summarizes a large number of observations
Theories: models that explain and give the underlying causes for observations and laws
Atomic theory
Analytical vs Quantification: how much, makes how much involves measurement as
part of observation.
1g of H = 6.022x 10 ^23 atoms
QUESTIONS:
1. WHAT ARE THE STEPS IN SCIENTIFIC METHOD (overview):
2. Classify each statement: obs, hypo, laws, theories.
3. SCIENTIFIC THEORY: A gas is composed of small particles in constant motion.
4. WATER MOLECULE CONTAINS: 2 H + 1 oxygen.
5. AT ROOM TEMP WATER IS LIQUID BC: water repels each other AKA characteristics.
6. IS EVERYTHING CHEMICAL: T. IE] N2 78.1 %, 02 21 %, PENICAL(CARBON)
7. Mass equals reactions and products: chemical rxn we don’t loss any mass LAW of CONSERVATION
8. Where can you find chemicals? You can find chemicals in the hardware store, a chemical
stockroom, All around you and even inside of you
CHAPTER 2
DEFINITIONS:
Metric system vs SI units Mass kg kilogram, g grams
C > F > K * = temperature Time: Seconds: mins
Meter (m); length Volume: liters
,QUESTIONS:
1 m = 100cm > 1m ^3 =
[ 100 x 100 x100 ] =
1000,000 cm ^3
1 kg = 1000 g
454 g = 1 lb.
1 km = 1000 m
0.1 L = 1 dL
5983.0 move decimal to the left. =
5.9X10^-3 move decimal to the left
0.0059 move decimal to the right. =
5.9X10^3 move decimal to the right
2.705 mg > kg
10^-3mg > 1000kg = 10 ^-6
1g /1000 mg > 1kg / 1000 g
= 0.000002705 vs 2.705 x 10 ^-6
significant figures (digits): 0.010101
o (zeros to the right of a nonzero number) that fall after a
decimal point are significant.
o 005.10 03.00
o Trailing zeros that fall before a decimal point are significant.
o 50.00 1700.24
o 0.0005 has only one significant digit.
o 350= 3.5×102 to indicate two significant figures or as
3.50×102 to indicate three
Multiplication or division Addition or Subtraction
, D=m/v
1.2 KG / 33.1 CC (ml) > D = g/ml
1000g/ 1kg > 1.2x 10^2 /33.1 =
2 sf = 36
MATTER AND ENERGY
CHAPTER 3
• 3.2 Define Matter: anything that occupies space and has mass.
Atoms: building blocks of matter.
Molecules: two or more atoms joined
• 3.2 Classify matter as S > L > G characteristics and examples ** chart **
o Ice, diamond, quartz, and iron: solid matter
o crystalline solids include salt and diamond. – well ordered, 3D structure
o amorphous solids include glass, rubber, and plastic. – no long range order
o Water, gasoline, alcohol, and mercury: liquid matter
o Oxygen, helium, and carbon dioxide: gases.
Atomic/ Atomic/
Molecular Molecular
State Motion Spacing Volume Compressibility
Solid Oscillation/ Close: together Definite Definite Incompressible
about
fixed-point
Liquid Free to move Close; together Indefinite Definite Incompressible
another
Free to move Far apart Indefinite Indefinite compressible
relative to one
another
, • 3.3Classify matter as element , compound, or mixture define **
• Matter may be a pure substance, or it may be a
mixture.
• A pure substance may be either an element (Na,
H2 ) or a compound. Ie: water ionic vs NaCl
molecular)
• A mixture may be either homogeneous or
heterogeneous.
• Mixtures may be composed of two or more elements, two or more compounds (ie:H20), or a
combination of both.
• Compound: substance is composed of 2 or more elements in fixed, definite proportions.
• Element: pure substance that cannot be broken down into simpler substances.
3.4Distinguish between physical and chemical properties
• PP: doesn’t change composition: phase
change, boiling point of water, and boiling .
When water boils, it turns into a gas, but the
water molecules are the same in both the
liquid water and the gaseous steam.
• CP: changing its composition, chemical rxn:
The susceptibility of iron to rusting, and
rusting. When iron rusts, it turns from iron to iron(III) oxide.
• Substance changes it composition (the particles change from one type to another).
ANS:C P, P, P
• 3.5Distinguish between physical and chemical changes
• PP: matter changes its appearance but not its
composition. If you push the button on a lighter
without turning the flint, some of the liquid
butane vaporizes to gaseous butane. Since the
liquid butane and the gaseous butane are both
composed of butane molecules, this is a physical
change.
• CP: matter does change its composition.If you push the button and turn the flint to create a
spark, you produce a flame. The butane molecules react with oxygen molecules in air to form new
molecules, carbon dioxide and water. This is a chemical change.
