Percent Composition from Chemical Formulas

What is the main objective of learning percent composition?

• To find the boiling point of a substance.

• To determine the volume of each element in a substance.

• To determine the percent composition for each element in a substance given its formula.

• To calculate the density of a substance.

What is the formula for percent composition?

• Mass of the whole divided by mass of the part times 100

• Volume of the part divided by volume of the whole times 100

• Mass of the part divided by mass of the whole times 100

• Number of atoms of the part divided by number of atoms of the whole times 100

In the formula H2O, what is the mass of the hydrogen part?

• 1.01 amu

• 18.02 amu

• 2.02 amu

• 16.00 amu

What is the total mass of the H2O molecule?

• 20.00 amu

• 18.02 amu

• 16.00 amu

• 2.02 amu

What is the percent composition of hydrogen in H2O?

• 11.2%

• 88.8%

• 50%

• 22.4%

What is the percent composition of oxygen in H2O?

• 22.4%

• 50%

• 88.8%

• 11.2%

What is the mass of aluminum in aluminum oxide (Al2O3)?

• 48.00 amu

• 101.96 amu

• 53.96 amu

• 26.90 amu

What is the total mass of aluminum oxide (Al2O3)?

• 53.96 amu

• 48.00 amu

• 101.96 amu

• 26.90 amu

What is the percent composition of aluminum in Al2O3?

• 48.00%

• 53.96%

• 52.92%

• 26.90%

What should you bring to class after watching the video?

• Questions

• A calculator

• A notebook

• A periodic table