Stochiometry

C6H12O6(s) + 6O2(g)  6CO2(g) + 6 H2O(g) What do the coefficients mean? Ratio of reactants and products

Think of it like….. A recipe: all these together makes 60 cookies 2 1/4 cups all-purpose flour 1 teaspoon baking soda 1 teaspoon salt 1 cup (2 sticks) butter, softened 1 ½ cup packed brown sugar 1 teaspoon vanilla extract 2 large eggs 2 cups (12-oz. pkg.) NESTLÉ® TOLL HOUSE® Semi-Sweet Chocolate Morsels

So what if you want to make 90 cookies? 2.25 F + 1 NaHCO3 +1 NaCl + 1 B+.75 BS + 1V + 2E + 2 CC = 60 Ck

How to solve stoichiometry Balance Use mole ratios to find moles needed C6H12O6(s) + 6O2(g)  6CO2(g) + 6 H2O(g)

How to solve stoichiometry Balance Use mole ratios to find moles needed C6H12O6(s) + 6O2(g)  6CO2(g) + 6 H2O(g) For every 1 mole of glucose, 6 moles of oxygen must be burned, so if you have 2 mole C6H12O6 : 1mole C6H12O6 as x mole O2 :6 moles O2

Stoichiometry: Mole-Mole Problems N2 + 3H2 → 2NH3  How many moles of hydrogen, H2, are needed to react with 2.0 moles of nitrogen, N2?

 2KClO3 → 2KCl + 3O2 How many moles of oxygen are produced by the decomposition of 6.0 moles of potassium chlorate, KClO3?

Zn + 2HCl → ZnCl2 + H2 How many moles of hydrogen are produced from the reaction of 3.0 moles of zinc?

C3H8 + 3O2 → 3CO2 + 4H2  How many moles of oxygen are necessary to react completely with 4.0 moles of propane (C3H8)?

K3PO4 + Al(NO3)3 → 3KNO3 + AlPO4 How many moles of potassium nitrate are produced when 2.5 moles of potassium phosphate react?

What about Mass???? But what about mass? We have to change mass to moles before doing any ratio comparison. I think of it as a bridge. To get on the bridge, you change from grams to moles. To get off the bridge you change back.

Mole bridge

N2 + 3H2 → 2NH3  How many grams of hydrogen, H2, are needed to react with 6.0 grams of nitrogen, N2?

2KClO3 → 2KCl + 3O2 How many grams of oxygen are produced by the decomposition of 6.0 grams of potassium chlorate, KClO3?

Zn + 2HCl → ZnCl2 + H2 How many grams of hydrogen are produced from the reaction of 3.0 gramsof zinc?

C3H8 + 3O2 → 3CO2 + 4H2  How many grams of oxygen are necessary to react completely with 4.0 grams of propane (C3H8)?

K3PO4 + Al(NO3)3 → 3KNO3 + AlPO4 How many moles of potassium nitrate are produced when 2.5 moles of potassium phosphate react?