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STANDARD 5a
• Students know reactant atoms
and molecules interact to form
products with different chemical
properties
CHEMICAL REACTIONS
• The reactants are the atoms and
molecules that start a chemical change
or reaction
• The new substances that form in a
chemical change are called products
• During a chemical change or reaction,
atoms in the reactants rearrange as
chemical bonds break and new bonds
form
• The products of a chemical reaction
have different chemical and physical
CHEMICAL REACTIONS
55. The reactants of a chemical reaction
have
A chemical properties identical to the
products
B chemical properties different from
the
products
C the same chemical makeup as the
products
D no chemical bonds
ANSWER: B
CHEMICAL REACTIONS
56. Which is evidence that a chemical
reaction might have occurred?
A release of energy
B change in shape
C similarities in physical properties
D presence of ions
ANSWER: A
CHEMICAL REACTIONS
57. Which of the following statements is true
about the reaction shown in the diagram?
A The products are identical to the
reactants
B The atoms of the product rearrange to
form
new molecules
C The atoms of the reactants rearrange to
form
new molecules
D No chemical bonds are broken
ANSWER: C
STANDARD 5b
• Students know the idea of atoms
explains the conservation of
matter: in chemical reactions the
number of atoms stays the same
no matter how they are arranged,
so their total mass stays the same
CONSERVATION OF MATTER
• Conservation of matter states
that during a chemical reaction,
matter is neither created nor
destroyed
• The total number of atoms
stays the same before and after
the reaction
CONSERVATION OF MATTER
58. According to the principle of the
conservation of matter
A reactants have the same mass as
the
products
B reactants have more mass than the
products
C products have less mass than the
reactants
D products have more mass than the
reactants
ANSWER:
A
CONSERVATION OF MATTER
59. Which equation
shows that the total
mass during a
chemical reaction
stays the same?
A 1
B 2
C 3
D 4
ANSWER:
C
CONSERVATION OF MATTER
N2O5 + H2O → HNO3
60. Berta wants to balance the equation shown
above. Which number should she place in
front of HNO3 in order to balance the
equation?
A 1
B 2
C 3
D 4
ANSWER:
B
Chemical Reactions
61. According to the
law of conservation
of mass, what mass
of O2 is generated?
A 8g
B 16 g
C 200 g
D 216 g
ANSWER: B
STANDARD 5c
• Students know chemical reactions
usually liberate heat or absorb
heat
CHEMICAL REACTIONS
• If a chemical reaction results in the
release of energy, the reaction is called
an exothermic reaction
• This energy is often released as heat
and light into the surroundings, which
becomes warmer
• If a chemical reaction results in a net
absorption of energy, the reaction is
called an endothermic reaction
• The energy for the reaction is usually
absorbed from the surroundings, which
becomes cooler
CHEMICAL REACTIONS
• The graphs show energy changes in
endothermic and exothermic reactions.
• The “bump” in the graph represents the
activation energy, which is the minimum
amount of energy required to get the reaction
started
Exothermic Reaction
Endothermic Reaction
CHEMICAL REACTIONS
62. Burning wood is an exothermic
reaction because
A energy is absorbed
B energy is released
C the reaction requires energy to keep
going
D Activation energy is not required
ANSWER: B
CHEMICAL REACTIONS
63. In an endothermic reaction,
A the products give off heat
B mass is not conserved
C the products have less energy than
the
reactants
D the products have more energy than
the
reactants
ANSWER: D
CHEMICAL
REACTIONS
64. The graphs show the
energy changes that
occur during a chemical
reaction. Which graph
best describes a
chemical reaction that
absorbs energy?
ANSWER:
D
CHEMICAL REACTIONS
65. Which of the following is true of both
exothermic and endothermic reactions?
A They absorb heat
B They release heat
C They require some energy to start
D They use more energy than they
produce
ANSWER: C
STANDARD 5d
• Students know physical
processes include freezing and
boiling, in which a material
changes form with no chemical
reaction
PHYSICAL CHANGES
• A physical change differs from a
chemical change in that chemical
bonds are neither broken nor
formed
• The appearance of the substance
will change, but not its chemical
makeup
• When water changes from a liquid
to a solid, the appearance changes,
but the ice and liquid water have
Chemical Reactions
Freezing, melting and
boiling are NOT
chemical reactions.
They are physical
changes.
PHYSICAL CHANGES
• A mixture is made of two or more
substances that are together in the
same place but are not chemically
combined: salad, pizza
• Making a mixture is a physical
change because the parts of the
mixture can be separated
• A solution is a uniform mixture that
has the same properties
throughout: salt water
PHYSICAL CHANGES
66. A change of state is a physical
change because
A the parts of the mixture can be
separated
B the atoms of the substance form new
chemical bonds
C the boiling point of the substance
changes
D the chemical makeup of the
substance stays the same
ANSWER: D
PHYSICAL CHANGES
67. David stirs a spoonful of sugar into a
glass of lemonade. As he stirs, the
sugar disappears. What type of change
is occurring?
A chemical change
B creation of matter
C destruction of matter
D physical change
ANSWER: D
PHYSICAL CHANGES
68. During boiling, liquid water turns
to water vapor. This is an example
of
A physical change
B chemical change
C chemical equation
D chemical formula
ANSWER:
A
STANDARD 5e
• Students know how to determine
whether a solution is acidic, basic,
or neutral
ACIDS AND BASES
• Properties of acids:
– Taste sour
– Corrosive
– Conduct electricity
– pH range of 1.0 - 6.9
– Changes blue litmus paper to red
ACIDS AND BASES
• Properties of bases:
– Tastes bitter
– Feels slippery
– Conducts electricity
– Corrosive
– pH range of 7.1 – 14.0
– Changes red litmus paper to blue
ACIDS AND BASES
• If the pH of a solution is 7.0 then
the solution is considered neutral
• Water has a pH of 7.0
ACIDS AND BASES
71. Which of the following things could be
used to determine whether a substance
is an acid or a base?
A an indicator
B litmus paper
C pH meter
D all of the above
ANSWER: D
ACIDS AND BASES
72. These data indicate that gastric juice
is a
A strong acid
B strong base
C weak acid
D weak base
ANSWER: A
ACIDS AND BASES
73. A substance that turns red litmus
paper blue is
A an acid
B a base
C an indicator
D a solvent
ANSWER:
B
STANDARD 6a
• Students know that carbon,
because of its ability to combine
in many ways with itself and other
elements, has a central role in the
chemistry of living organisms
CHEMISTRY OF LIVING
THINGS
• CARBON - has four valence
(outer) electrons and so it can
make four bonds
• Carbon atoms bonded together
with single, double, or triple bonds
can form straight chains,
branched chains, or rings
• Carbon’s ability to form four
bonds results in millions of
different shaped carbon-based
molecules that allow them to have
many different functions in living
C
CHEMISTRY OF LIVING
THINGS
74. Unlike the atoms of most other
elements, carbon atoms have which
number of bonding electrons?
A 1
B 2
C 3
D 4
ANSWER: D
CHEMISTRY OF LIVING
THINGS
75. Carbon-based molecules have a wide
range of chemical properties because
they
A have covalent bonds
B have the same shape
C can form many different shapes
D always form straight chains
ANSWER: C
STANDARD 6b
• Students know that living
organisms are made of molecules
consisting largely of carbon,
hydrogen, nitrogen, oxygen,
phosphorus, and sulfur
CHEMISTRY OF LIVING
THINGS
• An organic compound contains
carbon
• Organic compounds are found in all
living organisms
• Organic compounds include
hydrocarbons, alcohols, organic
acids, and polymers
Other Important Atoms in Living Things
Most organic molecules in living
things contain
carbon
nitrogen
sulfur
hydrogen
oxygen
phosphorus
NCHOPS
Chemistry of Living Things
76. Compounds that contain the element
carbon are called
A organic compounds
B polar molecules
C nonpolar molecules
D hydrocarbons
ANSWER: A
Chemistry of Living Things
77. Which chemical formula does not
represent an organic compound?
A CH3OH
B NH3
C C6H14
D CHCl3
ANSWER:
B
Chemistry of Living Things
78. Which of the following elements
is not an important component of
organisms?
A nitrogen
B oxygen
C phosphorus
D potassium
ANSWER: D
STANDARD 6c
• Students know that living
organisms have many different
kinds of molecules, including
small ones, such as water and
salt, and very large ones, such as
carbohydrates, fats, proteins, and
DNA
Chemistry of Living Things
• Carbohydrates are polymers made of
smaller molecules called glucose. Includes
sugars, starch, and cellulose. Provides
energy for living organisms
• Proteins are polymers made up of smaller
molecules called amino acids. Proteins are
used to build and repair body parts
• Lipids are polymers made from three fatty
acids and alcohol named glycerol. Lipids
include fats, oils, and waxes and are used to
store energy for living organisms
• Nucleic acids are very large polymers made
from four smaller molecules called
nucleotides. Two types: DNA and RNA.
Carries genetic information
Chemistry of Living Things
• Smaller molecules that living organisms
need to survive include water, vitamins,
minerals, and salts
• Most chemical reactions that occur in
living things take place in water
• Vitamins and minerals serve as helper
molecules in many life processes
• Salts are required for many functions,
such as contracting muscle, transmitting
nerve impulses, and balancing blood pH
Chemistry of Living Things
79. Which of the following is the smallest
molecule?
A
protein
B
sugar
C
salt
D
carbohydrate
ANSWER: C
Chemistry of Living Things
80. Which molecule is NOT a chemical
used by living organisms?
A lipid
B nucleic acid
C carboxylic acid
D protein
ANSWER: C
Chemistry of Living Things
82. Which of the following kinds of
chemical compounds does not contain
carbon?
A sugar
B lipid
C water
D protein
ANSWER: C