1. Percent Composition

2. What is it? Percent composition is the percent by mass of each element present in a compound.

3. Glucose, C 6 H 12 O 6 1.figure out the molar mass from the formula. 2.figure out the grams each atom contributes by multiplying the atomic weight by the subscript. 3.divide the answer for each atom by the molar mass and multiply by 100 to get a percentage.

4. Molar Calculation Examples

5. How many grams are in 2.3x10 -4 molecules of calcium phosphate (Ca 3 PO 4 )?

6. How many moles are in 98.3 g of aluminum hydroxide Al(OH) 3 ?

7. How many grams are in 238 moles of arsenic?

8. How many grams are in 4.63 x 10 24 molecules of CCl4?

9. How many grams in are 8.2x10 22 molecules of N 2 I 6 ?