2.  All stoichiometry problems start with a balanced equation.  You must check for this!  If it is not balanced, BALANCE IT!

3.  Can change coefficients but CANNOT change subscripts  Example ◦ 3S + 2 Fe  Fe 2 S 3 S S S Fe Fe 2 S 3

4.  Al + CuO  Al 2 O 3 + Cu  ____________________________

5.  H 2 + O 2  H 2 O _______________________

6.  Remember what an equation actually means ◦ Mg + S  MgS ◦ One _____________reacts with one ___________ creating one formula unit of MgS  But ◦ This also means that one mole of _________ reacts with one mole of ___________ to form one mole of _______ formula units. ◦ 1 mol Mg, 1 mol S, and 1 mol MgS are stoichiometry equivalents Equations and the Mole

7.  What about the equation ◦ C 3 H 8 + 5O 2  3CO 2 + 4H 2 O ◦ Now, ____ mol C 3 H 8, _____ mol O 2, _____ mol CO 2, and _______ mol H 2 O are stoichiometry equivalents

8.  As stoichiometry equivalents, they can be used in a conversion factor  __________________ Conversion Factors ◦ One equivalent is placed on top and one on bottom ◦ Allows us to move from one compound to another in a balanced equation

9. Given the equation: MgCl 2 + 2 AgNO 3  Mg(NO 3 ) 2 + 2 AgCl What is the mass of AgCl produced if 24g of MgCl 2 is reacted with excess AgNO 3 ? What amount of MgCl 2 will react with 3.85 g AgNO 3 ?

10.  So far we have been assuming that we have an excess of all the other reactants  This is not often true….often you have a set amount of both reactants ◦ Each amount would lead you to a different amount of product ◦ Must use the number that is ___________

11. Given the equation: MgCl 2 + 2 AgNO 3  Mg(NO 3 ) 2 + 2 AgCl How much AgCl will be produced if 28g of MgCl 2 is reacted with 51g of AgNO 3 ?

12.  Yield is the amount of product that you get from a reaction  Theoretical yield is the amount that you should get based on using stoichiometry  Actual yield is the amount of product actually attained during an experiment

13.  Calculated by taking ◦ _____________________________________

14. Given the equation: MgCl 2 + 2 AgNO 3  Mg(NO 3 ) 2 + 2 AgCl What is the percent yield of Mg(NO 3 ) 2 if 168.4 g of AgNO 3 is reacted to produce 47.2g of Mg(NO 3 ) 2 ?