Understanding Percent Composition and Empirical Formulas

What is the percent composition of chlorine in NaCl?

• 39.34%

• 60.66%

• 50%

• 25%

How do you calculate the percent composition of an element in a compound?

• Divide the total mass of the compound by the mass of the element and multiply by 100

• Divide the mass of the element by the total mass of the compound and multiply by 100

• Multiply the mass of the element by the total mass of the compound

• Add the mass of the element to the total mass of the compound and divide by 100

• 11.19%

• 88.81%

• 50%

• 25%

• CH

A compound is found to contain 40% carbon, 6.7% hydrogen, and 53.3% oxygen by mass. What is the empirical formula of the compound?

• 27.29%

• 72.71%

• 44.01%

• 12.01%

To determine the empirical formula of a compound, which of the following information is NOT necessary?

• The percent composition of each element in the compound

• The molecular weight of the compound

• The color of the compound

• The molar mass of each element in the compound

A 100 g sample of a compound contains 85.7 g of nitrogen and 14.3 g of hydrogen. What is the empirical formula of the compound?

• NH

• 25%

• 75%

• 14.43%

• 85.57%