1. Quantities in Chemistry
Stoichiometry by any other name!

2. The Mole How do you measure something? Mass: kilograms, grams
Volume: liters, mLs, cm3,
Count: particles, moles
Remember the mole: 6.022x1023
This is Avogadro’s Number

3. Stoich…measuring So what do we need to be able to handle?
Can you calculate molar mass of a compound?
Can you take a mass into convert it into moles?
Can you take a volume of a gas and convert it into moles?
Can you balance a chemical equation?
IF the answer to these is yes, you can handle most stoichiometry problems you are likely to see

4. Grams to moles
You will need to be able to calculate the molar mass of the material under discussion
Set up simple equation:
(x grams AB)(1mole AB/molar mass grams AB)
Multiplying this has grams cancel out, leaving moles AB.

5. Moles to Moles If our reaction is AB  A + B
Then you would set up this equation:
(molesAB)[(coefficient A)/(coefficient AB)] which would cancel out and yield Moles A produced
(Yes, it could be B instead, same type pathway)

6. Moles back out to grams Following from the last step:
(Moles A)[(molar mass A)/(1 mole A)] yields mass of A produced by the decomposition reaction

7. UNITS!! Make sure you label all numbers with their correct units
They will need to cancel out! If you get something like (moles)2 / grams, you know something is wrong (in this case, inverted)