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

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

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 H2 + O2  H2O

Formation of Water 2H2 + 1O2  2H2O 

Formation of Water 2H2 + 1O2  2H2O

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

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

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.

_2_ NaOH + _1_ H2SO4  _2_ H2O + _1_ Na2SO4 10 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 = 54.06 g H2O 200 g NaOH 2 mol NaOH 18.02 g H2O