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Balancing Chemical Equations Notes

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					Mr. Chapman                                                                  Chemistry 20
Balancing Chemical Equations

Balancing Chemical Equations
Physical Properties of Matter

The physical properties of matter include things that we can generally detect with our
senses and involve no chemical change, such as:

                                                 


                                                 


                                                 


   


Physical changes involve no change in the identity of the substance. Examples include
the fact that _______, ________, and __________ are all water.

Chemical Change

    Atoms in the reactants are rearranged to form one or more different
       _______________

    Old bonds are broken; new bonds form

       Examples:
Mr. Chapman                                                                            Chemistry 20
Balancing Chemical Equations

Classify each of the following as a:

1) physical change or 2) chemical change

A. ____ a burning candle

B. ____ melting ice

C. ____ toasting a marshmallow

D. ____ cutting a pizza

E. ____ boiling water


 A CHEMICAL REACTION IS A PROCESS IN WHICH AT LEAST
   ONE NEW SUBSTANCE IS PRODUCED AS A RESULT OF A

                                 CHEMICAL CHANGE

COPY THE SKETCH SHOWN ON THE CHEMICAL REACTION SLIDE WITH CIRCLES OF TWO DIFFERENT COLOURS, SHOWING
THE RELATION IN A CHEMICAL REACTION BETWEEN THE REACTANTS AND THE PRODUCTS.
Mr. Chapman                                                        Chemistry 20
Balancing Chemical Equations

Reading a Chemical Equation

                 4 NH3 + 5 O2          
                                             4 NO + 6 H2O

  Four ___________ of NH3 react with five ___________ O2 to
  produce four __________ NO and six _____________ of H2O

                                       or

 Four ________ NH3 react with 5 ________ O2 to produce four
                       ________ NO and six ________ H2O

A balanced chemical equation has ____________________________________________

_______________________________________________________________________.

       Al    +     S          Al2S3        Not Balanced

       2Al +      3S          Al2S3        Balanced
Mr. Chapman                                                                 Chemistry 20
Balancing Chemical Equations

Law of Conservation of Mass




Steps in Balancing an Equation

     1. Count the number of atoms of each element on each side of the chemical
        equation
     2. Determine which elements have an unbalanced number of atoms on each side
     3. Place coefficients in front of compounds to balance the number of atoms on each
        side of the equation
     4. Always save oxygen and hydrogen for the end! This typically makes it easier.

Balance Each Equation

A.    Mg     +     N2           Mg3N2

B.    Al     +     Cl2        AlCl3

C. Fe2O3 + C                    Fe + CO2

D.    Al + FeO                  Fe +    Al2O

E.    Al + H2SO4                Al2(SO4)3 + H2

				
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