1. Chem Catalyst 1) How many grams does 3.24 mol of carbon weigh? 2) How many particles are in 3.24 mol of carbon dioxide?

2. Today’s Agenda: 1. Catalyst 2. Quiz 3. Notes- percent composition

3. Percent Composition/Mass Percent - The percent by mass of each element in a compound. (mass of part) ÷ (mass of whole) x100

4. Percent Composition When a 13.60g sample of magnesium oxide is decomposed, 5.40g of oxygen are obtained. What is the percent composition of this compound? 1) Find the mass of each element. 2) Find the mass of the compound. 3) Calculate.

5. Percent Composition When a 13.60g sample of magnesium oxide is decomposed, 5.40g of oxygen are obtained. What is the percent composition of this compound?

6. Percent Composition: From Formula 1) Find the total molar mass for each element. 2) Divide by molar mass of compound. 3) Multiply by 100.

7. Percent Composition from Formula Find the percent composition of propane (C 3 H 8 ).

8. Percent Composition from Formula: Your turn! Find the percent composition of iron (II) oxide (FeO). Find the percent composition of iron (III) oxide (Fe 2 O 3 ).