Percent Composition

The percentage composition of oxygen in air is

• 20%

• 21%

• 22%

• 23%

The composition of nitrogen gas in the atmosphere is

• 77%

• 61

• 78%

• 79%

Complete the formula for % Composition.

a

b

c

total mass of compound

100

mass of element

What is the percent composition of hydrogen in water (H2O)?

• 11.11%

• 88.89%

• 33.33%

• 66.67%

In a compound with the formula C6H12O6, what is the percent composition of carbon?

• 40%

• 50%

• 60%

• 70%

Which element has the highest percent composition in the compound NaCl?

• Sodium

• Chlorine

• Both are equal

• Cannot be determined

If a sample contains 10 grams of hydrogen and 90 grams of oxygen, what is the percent composition of hydrogen?

• 10%

• 20%

• 30%

• 40%

What is the percent composition of nitrogen in ammonia (NH3)?

• 82.35%

• 17.65%

• 50%

• 25%

In the compound CO2, what is the percent composition of oxygen?

• 72.73%

• 27.27%

• 50%

• 66.67%

A compound is made of 40% sulfur and 60% oxygen. What is the percent composition of sulfur?

• 40%

• 60%

• 50%

• 70%