1. WHAT IS STOICHIOMETRY?

2. INTERPRETING BALANCED CHEMICAL EQUATIONS
STOICHIOMETRY IS THE STUDY OF THE QUANTITATIVE, OR MEASURABLE, RELATIONSHIPS THAT EXIST IN CHEMICAL FORMULAS AND CHEMICAL REACTIONS.
N2H4 + 2 H2O2 -> N2 + 4 H2O
The coefficients can indicate the following:
1 molecule N2H4 + 2 molecules H2O2 -> 1 molecule N2 + 4 molecules H2O
1 mole N2H4 + 2 moles H2O2 -> 1 mole N2 + 4 moles H2O
32 g N2H4 + 2(34 g) H2O2 -> 28 g N2 + 4 (18 g) H2O

3. HOW DO WE CALCULATE THE AMOUNT OF PRODUCT?

4. WHAT IS A LIMITING REACTANT?
The reactant that limits the amount of product formed
The reactant that in an experiment is all used up

5. Percent Yield
Measures the efficiency of a reaction carried out in the lab
Theoretical yield – the maximum amount of product that can form during a reaction (calculated)
Actual yield – how much actually forms
Factors causing % yield to be less than 100
Reaction not completing
Impure reactants
Loss of product during filtration
Careless measurement

6. HOW DO WE DETERMINE PERCENT YIELD?
Although you can determine the amount of product that will be produced in a chemical reaction, in reality, that calculated amount is not always the actual amount obtained from the reaction.

7. Thermochemical Equation
Shows the amount of heat produced or absorbed by a reaction
Every reactant will have a certain heat content, or enthalpy (H)
The change in enthalpy (H) will tell us if the reaction is exo or endothermic

8. If H is positive, reaction is endothermic (heat is a reactant)
Change in Enthalpy
If H is positive, reaction is endothermic (heat is a reactant)
If H is negative, reaction is exothermic (heat is a product)