Notes
SPI 0807.9.10
& Products
Press the Reactants
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Button to
SPIAdvance
0807.9.11through
Law of Conservation
of Mass
the Presentation!

Look at the formula below.
Identify the reactants and products
Contrast reactants and products (how are they different?)
C + O2
CO2
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Notes
SPI 0807.9.10 Reactants & Products
SPI 0807.9.11 Law of Conservation of Mass

 Contrast reactants and products (how are they different?)
Reactants-are the starting materials in a chemical reactions
 Remember: the arrow ALWAYS points away from the reactants!
C + O2
CO2
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Notes
SPI 0807.9.10 Reactants & Products
SPI 0807.9.11 Law of Conservation of Mass

1) Contrast reactants and products (how are they different?)
Products- are the substances formed in a chemical reaction
 Remember: the arrow ALWAYS points towards the products!
C + O2
CO2
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Review
Questions
SPI 0807.9.10 Reactants & Products
SPI 0807.9.11 Law of Conservation of Mass

Title: LOCOM Review Questions
Instructions:
(A) Write this assignment title on your paper.
(B) Then number your paper from 1 to 17.
(C) Write the answers on your paper
(D) Review the previous slide(s) to help you
(1) ________ and _______ are the 2 parts of all chemical reactions.
(2) _________ are the starting materials in a chemical reaction.
(3) _________ are the substances you produce in a chemical reaction.
(4) In chemical reactions, the arrow points away from the _______.
(5) In chemical reactions, the arrow points towards the _________.
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Notes
SPI 0807.9.10 Reactants & Products
SPI 0807.9.11 Law of Conservation of Mass

3 key Topics
Chemical symbols
Chemical Formulas
Chemical Equations
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Notes
SPI 0807.9.10 Reactants & Products
SPI 0807.9.11 Law of Conservation of Mass

Key Topics
Chemical symbols
Examples:
H is just a chemical symbol (for the element hydrogen)
O is just a chemical symbol (for the element oxygen)
Fe is just chemical symbol (for the element iron)
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Notes
SPI 0807.9.10 Reactants & Products
SPI 0807.9.11 Law of Conservation of Mass

Key Topics
Chemical formulas
Chemical symbols combined together =
chemical formulas
Examples:
Put the symbols H (hydrogen) and O (oxygen) together…
…and you get the formula for water… H2O
Examples:
Put the symbols Na (sodium) and Cl (chlorine) together…
...and you get the formula for sodium chloride… NaCl
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Review
Questions
SPI 0807.9.10 Reactants & Products
SPI 0807.9.11 Law of Conservation of Mass

Title: LOCOM Review Questions
Instructions:
-Write the answers on your paper
-Review the previous slide(s) to help you
(6) List 3 key topics that you need to know when learning about
chemical reactions.
(7) Write any two examples of chemical symbols.
(8) Write any two examples of chemical formulas..
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Notes
SPI 0807.9.10 Reactants & Products
SPI 0807.9.11 Law of Conservation of Mass

Key Topics
Chemical symbols & Chemical Formulas
Very Important!!!
symbols & formulas must be written correctly.
CO2= one carbon atom, two oxygen atoms
CO= one carbon atom, one oxygen atom
Co=one cobalt atom
2CO= two carbon atoms, two oxygen atoms
2CO2= two carbon atoms, four oxygen atoms
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Notes
SPI 0807.9.10 Reactants & Products
SPI 0807.9.11 Law of Conservation of Mass

Key Topics
Chemical symbols & Chemical Formulas
QUICK REVIEW!
CO2
Is this a chemical symbol or a chemical formula?
Is this a mixture or a compound?
How many total atoms does it contain?
Identify the individual atoms.
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Notes
SPI 0807.9.10 Reactants & Products
SPI 0807.9.11 Law of Conservation of Mass

Key Topics
Chemical symbols & Chemical Formulas
QUICK REVIEW!
CO2
Is this a chem symbol or chem formula?
It is a chemical formula
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Notes
SPI 0807.9.10 Reactants & Products
SPI 0807.9.11 Law of Conservation of Mass

Key Topics
Chemical symbols & Chemical Formulas
QUICK REVIEW!
CO2
Is this a mixture or a compound?
It is a compound
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Notes
SPI 0807.9.10 Reactants & Products
SPI 0807.9.11 Law of Conservation of Mass

Key Topics
Chemical symbols & Chemical Formulas
QUICK REVIEW!
CO2
How many total atoms does it contain?
Three
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Notes
SPI 0807.9.10 Reactants & Products
SPI 0807.9.11 Law of Conservation of Mass

Key Topics
Chemical symbols & Chemical Formulas
QUICK REVIEW!
CO2
Identify the individual atoms.
= one
carbon atom, two oxygen atoms
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Review
Questions
SPI 0807.9.10 Reactants & Products
SPI 0807.9.11 Law of Conservation of Mass

Title: LOCOM Review Questions
Instructions:
-Write the answers on your paper
-Review the previous slide(s) to help you
(9) Is H2O a chemical symbol or chemical formula?
(10) The chemical formula CO2 is a compound. How can you tell?
(11) H2O contains three total atoms. How many hydrogen atoms does
it contain, and how may oxygen atoms does it contain?
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Notes
SPI 0807.9.10 Reactants & Products
SPI 0807.9.11 Law of Conservation of Mass

Key Topics
Chemical Equations
Chemical formulas combined together =
chemical equations
Examples:
Equation: 2H2 + O2
2H2O
Equation: 2Na + Cl2
2 NaCl
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Notes
SPI 0807.9.10 Reactants & Products
SPI 0807.9.11 Law of Conservation of Mass

2 parts of chemical equations
(1) reactants
(2) products
Reactants: are the things you are combing together…the
things you start with in a chemical reaction
Products: are the things that you produce in a chemical
reaction… the things you end up with
Example: 2H2 + 02
2H20
Products (water)
Reactants (H & O)
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Review
Questions
SPI 0807.9.10 Reactants & Products
SPI 0807.9.11 Law of Conservation of Mass

Title: Acid Review Questions
Instructions:
-Write the answers on your paper
-Review the previous slide(s) to help you
(12) What do we call the substances created in a chemical reaction?
(13) When you see two chemical symbols being added together this
is called a chemical __________?
(14) Copy down the chemical equation shown below in.
Next draw a circle around the reactants.
Then draw a rectangle around the products.
2H2 + O2
2H2O
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2
Notes
SPI 0807.9.10 Reactants & Products
SPI 0807.9.11 Law of Conservation of Mass

Chemical Equations show how chemical reactions occur, and they
must obey the LAW OF CONSERVATION OF MASS!
The law of conservation of mass:
Atoms are never lost or gained in a chemical reaction…
… they are just rearranged.
Example: Look at the following bad/wrong equation.
It DOES NOT obey the law of conservation of mass and is called
unbalanced. This equation is wrong.
(count the atoms on each side!)
H2 + O2
H2O
2 & 2
2&1
Four is not equal to three!
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Notes
SPI 0807.9.10 Reactants & Products
SPI 0807.9.11 Law of Conservation of Mass

Balancing Equations: make sure the number of reactants atoms equals the
number of products atoms. If they are not equal, you must balance the
equation
(See below for an example)
Same equation as the previous slide, but now I have balanced it
(count the atoms on each side)
2H2 + O2
2H2O
4 Hyd + 2 Oxy yields 4 Hyd and 2 Oxy
6 reactant atoms is equal to 6 product atoms!
 Coefficient=number in front of a chemical symbol or formula
(tells you to multiply)
Subscript=small number below and to the right of a chemical symbol
(tells you the number of atoms)
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Review
Questions
SPI 0807.9.10 Reactants & Products
SPI 0807.9.11 Law of Conservation of Mass

Title: LOCOM Review Questions
Instructions:
-Write the answers on your paper
-Review the previous slide(s) to help you
(15) The law of conservation mass states that atoms are
never _____ or gained in a chemical reactions, instead the atoms are
merely ____________.
(16) Look at the chemical equation shown below. It is unbalanced.
How can you tell that this equation is unbalanced?
2H2 + O2
H2O
(17) Look at the balanced chemical equation shown below.
How can you confirm that it is balanced?
2Na + Cl2
2 NaCl
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2
Review
Questions
SPI 0807.9.10 Reactants & Products
SPI 0807.9.11 Law of Conservation of Mass

Instructions:
(A) Click on the study guide link below.
(B) Do the study guide until you earn a 100 on it
Study Guide Link: See the link under my April 11th
website entry
(C) Next click on the class work assignment below
(D) When complete, click the "Grade & Submit" button.
(E) Your grade will be emailed to Mr. Elliott
Class work Link: See the link under my April 11th
website entry
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