Introduction to Stoichiometry

What is Mole Ratio?How can I determine mole ratio from

balanced equation?

Can you cook? Can you follow a recipe?

How do ingredients form products?

Reactants Products

What is used to make “products” cookies?

What is Stoichiometry?• Wikipedia Answer: branch of chemistry that

deals with the relative quantities of reactants and products in chemical reactions

• My Answer: recipe for reactions

Stoichiometry ~ Cooking

How do you make a ham sandwich?

Gather Ingredients

(Chemical Reactants)

Combine Ingredients

(Rearrange Reactants)

Make Sandwich

(Form Products)

Check Kitchen Khemistry HW

• What is the ratio of bread to ham? 2:1

What is Mole Ratio?• Balanced equations reveal molar ratios!• Molar Quantities are derived from Coefficients• Moles = Coefficients

Balance this equation!

_____ N2 (g) + _____H2 (g) ______ NH3 (g)1 3 2

ATOMS

MOLECULES

MOLES

2 6 8

1 3 2

1 3 2

USE the Balanced Equation!

_____ N2 (g) + _____H2 (g) ______ NH3 (g)

What is the molar ratio of Nitrogen to Hydrogen?

1 3 2

Nitrogen : Hydrogen

1 : 3

Importance of Molar Ratios• Molar ratios help to connect amounts of reactants.• How many sandwiches could I make with 4 slices of

bread and 2 slices of ham?

2 SandwichesRatio of Bread: Ratio of Ham

2: 1

Apply to the Balanced Equation

How many moles of Ammonia could I make from 3 moles of Nitrogen?

_____ N2 (g) + _____H2 (g) ______ NH3 (g)1 3 2

GIVEN

3 mol N2

mol N2

mol NH3

1

26 mol NH3