**1 GFW=1 mole = 6.022 X10**^{23}
particles

*Chemical
recipes: How many ways can you cook a mole?*

Seriously,
stoichiometry is the way we calculate chemical recipes and to make sure that
every molecule or ion has a partner. That way we know how much product we will get out of it. Every problem is pretty much
the same. Do these steps every time.

*The Steps:
*

1. ** Correct compound formulas** (all charges add to zero)

2. ** Balanced equation** ( same number of same kind of atoms on both sides of the equation)

3. Start with the ** mass that you are given**: the known

4. ** Calculate the GFW** (gram formula weight also known as molar mass)

5. ** Divide by GFW** to get number of moles present.

6. Multiply by the ** mole ratio** (the ratio from the balanced equation telling you how much unknown you get from how much known
)

7. Convert from moles of unknown to mass of unknown by ** multiplying by the GFW** of the unknown.

*Example*

If you decompose
(using electricity) 10.0 grams of water, how many grams of oxygen will result?

2H_{2}O -->
2H_{2} + O_{2 }(Steps 1
and 2: Formulas and balanced equation)

Now set up a factor label
problem