1. LIMITING REACTIONS INB PAGE 43

2. ESSENTIAL QUESTION: Why is the limiting reactant not always the reactant with fewer moles?

3. LIMITING REACTIONS Limiting reactant: The reactant that limits how much of the product can be produced. Excess reactant: The substance that is not completely used up in the reaction.

4. EXAMPLE PROBLEM If 6.0 mol of HF is added to 4.5 mol of SiO2, which is the limiting reactant?

5. 1) N 2 H 4 + H 2 O 2 => N 2 + H 2 O A) What is the limiting reactant when.750 mol of N 2 H 4 is mixed with 0.500 mol of H 2 O 2 ? B) How much of the excess reactant remains unreacted? C) How much of each product is produced?

6. 2) Fe + H 2 O => Fe 3 O 4 + H 2 A) When 36.0 g H 2 O is mixed with 67.0 g Fe, Which is the limiting reactant? B) What is the mass of iron oxide produced? C) What mass of the excess reactant remains when the reaction is complete?

7. PERCENT YIELD Theoretical Yield: The maximum amount of product that can be produced. Actual yield: The amount of product obtained from the reaction. Percent Yield: Actual Yield_ X 100 Theoretical Yield

8. Example: C 6 H 6 + Cl 2 => C 6 H 5 + HCl What is the theoretical yield(g)? If the actual yield is 38.8g, what is the percent yield of C 6 H 5 ?