What is the empirical formula of a compound that contains 40% carbon, 6.7% hydrogen, and 53.3% oxygen by mass?

• CH2O

The empirical formula of a compound is CH2O and its molar mass is 180 g/mol. What is its molecular formula?

• C6H12O6

Which of the following best describes an empirical formula?

• Shows the actual number of atoms of each element
• Shows the simplest whole-number ratio of atoms
• Shows only the elements present
• Shows the total mass of the compound

A compound is found to contain 54.5% carbon, 9.1% hydrogen, and 36.4% oxygen by mass. What is the empirical formula?

• C2H4O

The empirical formula and the molecular formula of a compound can sometimes be the same.

If a compound contains 85.7% carbon and 14.3% hydrogen by mass, what is its empirical formula?

• CH2

A compound contains 92.3% carbon and 7.7% hydrogen by mass. Its molar mass is 78 g/mol. What is its molecular formula?

• C6H6

Which of the following is NOT true about molecular formulas?

• They show the actual number of atoms of each element
• They are always multiples of the empirical formula
• They show the simplest whole-number ratio of atoms
• They can be the same as the empirical formula

If the empirical formula of a compound is NO2 and its molecular mass is 92 g/mol, what is the molecular formula?

• N2O4

A hydrocarbon undergoes complete combustion and produces 88 g of CO2 and 27 g of H2O. Which element is not present in the original hydrocarbon?

• Carbon
• Hydrogen
• Oxygen
• Nitrogen

The ratio of atoms in the empirical formula is always a whole number.

The empirical formula of glucose is C6H12O6.

If a compound has a molecular formula of C2H4O2, what is its empirical formula?

• C2H4O2
• C2H2O
• CH2O
• CHO

A sample of a compound contains 12 g of carbon, 2 g of hydrogen, and 16 g of oxygen. What is the empirical formula?

• CH2O

The molecular formula of a compound is always a whole-number multiple of the empirical formula.

When determining empirical formulas from combustion analysis, the amount of CO2 produced tells you the amount of carbon in the original sample.

If a compound's empirical formula is the same as its molecular formula, what does this indicate?

• The compound is an element
• The compound is very large
• The formula cannot be determined
• The empirical and molecular formulas are identical

A compound has an empirical formula of CH and a molar mass of 78 g/mol. What is its molecular formula?

• C2H2
• C3H3
• C6H6
• CH

Combustion analysis can be used to determine the empirical formula of organic compounds.

If a compound contains 24 g of carbon and 4 g of hydrogen, what is the empirical formula?

• C2H4
• CH2
• CH4
• C2H2