Empirical and Molecular Formulas Quiz

What does the molecular formula of a compound indicate?

• The total mass of the compound

• The simplest whole number ratio of atoms

• The type of chemical bonds present

• The number of atoms of each element in a molecule

How do you find the empirical formula from a molecular formula?

• Subtract the smallest subscript from the largest

• Add the atomic masses of all elements

• Divide all subscripts by the smallest number

• Multiply all subscripts by the smallest number

What is the empirical formula of ethine if its molecular formula is C2H4?

• C2H4

• C2H2

• CH2

• CH

What is the significance of the smallest number in a molecular formula when determining the empirical formula?

• It is used to divide all subscripts

• It is used to multiply all subscripts

• It is added to all subscripts

• It is subtracted from all subscripts

What is the empirical formula of a compound with a molecular formula of C2H6?

• C2H6

• CH3

• CH2

• C2H3

For the compound dybromoethane, what is the empirical formula if its molecular formula is C2H4Br2?

• CHBr

• C2H2Br

• CH2Br

• C2H4Br2

What is the first step in determining the molecular formula from the empirical formula?

• Multiply the empirical formula by the relative molecular mass

• Calculate the relative molecular mass of the empirical formula

• Divide the relative molecular mass by the empirical formula mass

• Add the atomic masses of all elements

If a compound has an empirical formula of CH2 and a relative molecular mass of 84, what is its molecular formula?

• C2H4

• C3H6

• C6H12

• C4H8

What is the relative molecular mass of the empirical formula CH2O?

• 30

• 44

• 60

• 18

If a compound has an empirical formula of CH2O and a relative molecular mass of 180, what is its molecular formula?

• C6H12O6

• C3H6O3

• C2H4O2

• C12H24O12