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Unit B: Matter & Chemical Change
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4.0 – Substances undergo a chemical
change when they interact to produce
different substances
C
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4.1 – Chemical Reactions
A. Introduction
1.
2.
3.
4.
5.
6.
A chemical reaction takes place when 2 or more
_________________ combine to form a NEW substance
(compound).
The materials at the START of a reaction are called the
_______________.
The materials produced AFTER the reaction has taken
place are called the _______________.
We can use chemical _______________ equations to show
a reaction has taken place.
The arrow will ____________ point towards the products.
Example:
_____________________________________________
_____________________________________________
7.
A _______________ change results from a chemical
reaction. Evidence that a chemical change has occurred
include:
a)
b)
c)
d)
A change in _______________
The formation of an _______________
The _______________ of a solid or a gas (bubbles)
The release or absorption of _______________
B. Endothermic and Exothermic Reactions
1.
2.
A chemical change, which releases energy, is called
_______________.
A chemical change, which absorbs energy, is called
_______________.
C. Chemical Changes Involving Oxygen
1.
Three different chemical reactions that occur when oxygen
reacts with other substances are:
a)
_______________– occurs when oxygen reacts with another
substance to form a new substance and give off ENERGY.
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b)
c)
_______________ - occurs when oxygen combines in the air
and reacts with a METAL
_______________ _______________ - occurs when
oxygen undergoes a chemical reaction in the cells in your body
2. The most _______________ word equation to remember
is:
_____________________________________________
_____________________________________________
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4.2 – Conservation of Mass in Chemical
Reactions
A. The Law of Conservation of Mass
_____________________________________________
_____________________________________________
2.
3.
4.
5.
(E
The law ties in well with the atomic theory, which states
that atoms are never _______________ or destroyed.
In a chemical reaction the atoms and molecules are simply
_______________ .
This law of conservation of mass however does not apply to
nuclear reactions, because there is some loss of mass:
____________________________________________
This was first suggested by Albert Einstein in his famous
equation:
_______________
is __________, M is _________, C2 is a ______________)
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6.
7.
A very tiny amount of _______________ is equal to a
very large amount of _______________.
In an _______________ system, some of the mass seems
to _______________ , when it is in the form of a gas.
4.3 – Factors Affecting the Rate of a
Chemical Reaction
A. Reaction Rate
1.
The speed of a chemical reaction is called the
_______________ _______________ .
a) _______________ of the reactants affects the rate
of all reactions (The higher the temperature the faster
the reaction rate).
b) _______________ _______________ of the
reactants affects the reaction rate (The more surface
in contact, the faster the reaction rate).
c) _______________ of the reactants affects the
reaction rate. (The higher the concentration, the faster
the reaction rate).
d) The presence of a _______________ affects the
reaction rate (Catalysts are substances that help a
reaction proceed faster).
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B. Catalysts
1.
2.
Catalysts are not _______________ in the reaction.
Types of reactions involving catalysts can be found in
_______________ and non-living things.
3. _______________ help in the reactions in the body,
which break down food.
4. They also get rid of _______________ in the body.
5. Catalase (an enzyme found in plant and animal cells) speeds
up the _______________ down of hydrogen peroxide into
harmless oxygen and water.
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