Stoichiometry

What?
"stoichio" = Greek for element
"metry"    = measurement
-about measuring the amount of substances that is involved in a reaction
-study of relationship between amount of reactants used in a chemical reaction and the amount of products produced by the reaction

BALANCED CHEMICAL EQUATIONS ARE REQUIRED

-shows the ratio of the molecules/moles of the substances in a chemical reaction

Ex 1. How many moles of HCl are required to react with 0.350 moles Zinc?

1) Write a balance equation

2) Make a road map in your head

3) Calculation

         1: 2 HCl_(aq) + 1 Zn_(s) ---> 1 ZnCl₂ + 1 H_2(g)

         3: 0.350 mol Zn x 2 mol HCl  =  0.700 mol HCl
                                     1 mol Zn

Ex 2. Using the same balanced equation. How many grams of ZnCl₂ will be produced in the reaction of HCl with 0.350 moles of Zinc?
          0.350 mol Zn x 1mol ZnCl₂ x 136.4 g ZnCl₂ = 47.7 g ZnCl₂
                                   1 mol Zn          1 mol ZnCl