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ELEMENTS AND THEIR ATOMS

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ELEMENTS AND THEIR ATOMS Powered By Docstoc
					                            ELEMENTS AND THEIR ATOMS
                          COMPOUNDS AND THEIR FORMULAS
                               CHEMICAL EQUATIONS


Here is the general form of all chemical equations:

                 Yields

A + B →C + D
Reactants                  Products

(Where there can be a varying number of items on the left and right sides of the
arrow)

There are other symbols we use in equations to tell us whether the reactants and
products are

Solids (s)
Liquids (l)
Gases (g)
Aqueous (dissolved in H2O) (aq)

2AgNO3 (aq) + K2CrO4 (aq) → Ag2CrO4 (s) + 2KNO3 (aq)

BALANCING EQUATIONS:
This is fun – honest!!!!!!
Why do we do it? We do this because atoms are conserved in chemical
reactions and we have to balance equations to make sure that this is the
case. (Besides which, chemicals really behave this way!)

We balance chemical equations by changing coefficients – NEVER,
NEVER, NEVER, NEVER, NEVER, NEVER, NEVER subscripts

Clue – When balancing equations, do H and O last, since they often
appear in more than one compound and starting with them can be very
challenging.

C4H10 + 13 O2 → 4CO2 + 5H2O
        2

2 C4H10 + 13 O2 → 8 CO2 + 10 H2O

				
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