Download 09 NOTES Balancing Equations COMPLETE

COMPLETE
BALANCING
EQUATIONS
PARTS OF A CHEMICAL EQUATION
REACTANTS
________________________________ - the ions ( elements ) being chemically combined
to make a new compound
PRODUCT
________________________________ - the new compound that results from combining
the reactants
Reactants
Li + O Product
Li2O
________________________________
Dilithium oxide
__________________________________
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BINARY COMPOUND
_________________________________–
a compound composed of two different elements
WRITING FORMULAS and BALANCING EQUATIONS
Write the symbol of the element with the positive oxidation number
1. ________________________________________________________________________
________________________________________________________________________
Write the symbol of the element with the negative oxidation number
2. ________________________________________________________________________
________________________________________________________________________
“Criss-cross the oxidation numbers for subscripts on the product side
3. ________________________________________________________________________
________________________________________________________________________
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Example:
To combine Li (lithium) and O (oxygen), do the following:
+1 + O-2
Li
_________________________________________________________________________
Li + O Li2O1
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Since oxygen’s subscript is 1, it is not written in the final version of the formula
_________________________________________________________________________
Li + O Li2O
( Two atoms of Li; one atom of O )
_________________________________________________________________________________________
_________________________________________________________________________________________
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To balance the Equations:
Reactants
Li
+ O
Product
Li2O
Label the diatomic element on the reactant side ONLY.
1. ________________________________________________________________________
You will be provided a list of diatomic element
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
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Reactants
Li
+ O2
Product
Li2O
Diatomic Subscript
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There must be the same number of atoms of each element on both
Remember: _______________________________________________________________
sides of the equation
_________________________________________________________________________
2 oxygen
4Li
+ O
2Li2O
4 lithium
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Using the Coefficients, balance the non-metal first, then balance the metal
2. ________________________________________________________________________
________________________________________________________________________
Reactants
Li
metal
4Li
Product
+ O2
Li2O
non-metal
+ O
2Li2O
Coefficients
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DIATOMIC ELEMENTS
__________________________________
- elements whose atoms exist in nature and
are always found in pairs
Diatomic Elements
Follow These Steps
Balancing Equations
Element
Symbol
Nitrogen
N2
1. Write the symbol for the metal, then a + sign
Oxygen
O2
2. Write the symbol for the nonmetal, then the Fluorine
F2
3. Write the compound formula (Example: NaCl)
Chlorine
Cl2
4. Do the “criss-cross” to label subscripts in the product
Bromine
Br2
5. Label the diatomics on the REACTANT SIDE ONLY
Iodine
I2
6. Balance the nonmetal first (Example: O2)
Hydrogen
H2
7. Balance the metal
8. Use Coefficients as needed
9. See examples in the notes
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