What is a chemical reaction

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What is a chemical reaction?
Definition A change in the chemical and
physical properties of a substance, or a
rearrangement of atoms into new substances.
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How do you know a chemical reaction has taken
place?
Color Change Heat Change Gas Produced Precipitate
Formed
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III. Types of Chemical Reactions
Todays Topic Mr. Moses finds and loses love.
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A. Synthesis Reaction - Two or more simple
substances combine to form a new more complex
one.
Edna
Moses
True Love
Ex Mg O2 -----gt MgO A B -----gt AB
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B. Decomposition Reaction - A complex substance
breaks down into two or more simpler substances.

True Love
Alone Again -(
Ex 2H2O ----gt 2H2 O2 AB ----gt A B
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C. Single-Replacement Reaction An uncombined
element replaces an element that is part of a
compound


New True Love
True Love
Not a Playa
Playa
Ex 2H2O 2Na ----gt 2NaOH H2 AB C ----gt BC
A
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D. Double-replacement Reaction Different atoms
in two different compounds replace each other.
In other words, two compounds react to form two
new compounds.


Ex AgNO3 NaCl ---gt AgCl NaNO3 AB- X Y-
-----gt A Y- X B-
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What type of reaction are these examples? Balance
each of the examples.
Na Cl2 --gt NaCl
H2O --gt H2 O2
Al Fe(NO3)2 --gt Al(NO3)3 Fe
Ca O2 --gt CaO2
(NH4)3PO4 Sr(OH)2 --gt Sr3(PO4)2 NH4OH
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The Final Thought
Although life may toss you curve balls, and you
may not always love the one you are with,
remember that it doesnt really matter. What
matters the most is Chem/Phys. The one and only
true love.