1. 10 9 8 7 6 5 4 3 2 1 3/11 Multistep Conversions Make 20 cookies!
1. Analyze the cookie recipe. If a baker wanted to make 40 cookies how much of the following would they need: eggs? cups of flour?
2. CALCULATE how many minutes are in 1 year by using a “string of conversion” factors. Show all work.
1 year
= ? min

2. Stoi - chi - om - me - try Stoy- key- ahm- meh- tree
Introduction to Stoichiometry
mass
balanced
The Law of Conservation of ________ and a _______________ equation allows us to calculate how much of substance reacts or is produced in a chemical reaction. These types of calculations are called _____________________ and use _______________ factors to solve for an unknown mass or # of moles. Balance the equation below so we can practice some stoichiometry:
stoichiometry
conversion
Stoi -
chi -
om -
me -
try
Stoy-
key-
ahm-
meh-
tree

3. H2 + O2  H2O Introduction to Stoichiometry mass balanced
The Law of Conservation of ________ and a _______________ equation allows us to calculate how much of substance reacts or is produced in a chemical reaction. These types of calculations are called _____________________ and use _______________ factors to solve for an unknown mass or # of moles. Balance the equation below so we can practice some stoichiometry:
stoichiometry
conversion
H O2  H2O

4. Formation of Water
2H2 + 1O2  2H2O 

5. Formation of Water
2H2 + 1O2  2H2O

6. 2H2 + 1O2  2H2O The coefficients are molar ratios!
Formation of Water
2H2 + 1O2  2H2O
2 molecules of H molecules of O2  2 molecules of H2O
2 x H x O2  2 x H2O
(6.022 x 1023)
(6.022 x 1023)
(6.022 x 1023)
mole
mole
mole
2 x H x O2  2 x H2O
The coefficients are molar ratios!
The balanced equation is like a recipe!

7. 2H2 + 1O2  2H2O 10.0 How much Oxygen is Required
If a chemist has ______ g of H2, how many g of O2 would be required for the reaction?
GIVEN
INFORMATION
____ H2  ____ H2
____ H2  ____ O2
____ O2  ____ O2
WHAT I WANT TO KNOW g
mol
mol
mol
mol g
10.0 g H2 1
mol H2 1
mol O2
32.00
g O2
= 79.2 g O2
mol O2
2.02
g H2 2
mol H2 1

8. Mass  Mole Conversions
g  mol
mol  mol
mol  g
10.0
79.2
SO, WE KNOW THAT FOR ______ g H2 TO FULLY REACT, ______ g O2 IS NEEDED.

10. _2_ NaOH + _1_ H2SO4  _2_ H2O + _1_ Na2SO410 9 8 7 6 5 4 3 2 1
3/6 Stoichiometry Error
_2_ NaOH + _1_ H2SO4  _2_ H2O + _1_ Na2SO4
A student sets up the stoichiometry calculation below to find out how much water is made if you start with 200 g of NaOH.
1. WRITE what 3 things they did wrong in their calculation.
200 g NaOH
1 mol NaOH
3 mol H2O
1 mol H2O
= g H2O
200 g NaOH
2 mol NaOH
18.02 g H2O