Molecular Formula

What is the process for determining the molecular formula from the empirical formula?

• Using the color of the compound to determine the molecular formula

• Dividing the molar mass of the empirical formula by 2

• Counting the number of atoms in the empirical formula

• Comparing the molar mass of the empirical formula to the molar mass of the actual compound

If the empirical formula of a compound is CH2O and its molar mass is 90 g/mol, what is its molecular formula?

• C4H8O4

• CH4O2

• C2H4O2

• C3H6O3

If the empirical formula of a compound is C2H5 and its molar mass is 58 g/mol, what is its molecular formula?

• C5H12

• C4H10

• C2H6

• C3H8

Explain the relationship between empirical formula and molecular formula.

• The empirical formula shows the simplest whole number ratio of the elements, while the molecular formula shows the actual number of each element in a molecule.

• The empirical formula is always the same as the molecular formula

• The empirical formula is used for organic compounds, while the molecular formula is used for inorganic compounds

• The molecular formula is used for ionic compounds, while the empirical formula is used for covalent compounds

If the empirical formula of a compound is NH2 and its molar mass is 32 g/mol, what is its molecular formula?

• N2H4

• NH4

• N2H2

• NH3

What information is needed to determine the molecular formula from the empirical formula?

• The molar mass of the compound

• The boiling point of the compound

• The color of the compound

• The state of matter of the compound

If the empirical formula of a compound is C3H6O and its molar mass is 102 g/mol, what is its molecular formula?

• C4H8O

• C3H6O

• C5H10O

• C6H12O2

What is the difference between empirical formula and molecular formula?

• Empirical formula shows the simplest whole-number ratio of the elements, while molecular formula shows the actual number of each type of atom in a molecule.

• Empirical formula is used for ionic compounds, while molecular formula is used for covalent compounds.

• Empirical formula and molecular formula are the same thing.

• Empirical formula shows the actual number of each type of atom in a molecule, while molecular formula shows the simplest whole-number ratio of the elements.

If the empirical formula of a compound is CH and its molar mass is 78 g/mol, what is its molecular formula?

• C6H6

• CH2O

• C4H4

• C3H3

How can you determine the molecular formula if you are given the empirical formula and the molar mass of a compound?

• Add the molar mass and the empirical formula mass together

• Ignore the molar mass and only use the empirical formula

• Subtract the molar mass from the empirical formula mass

• Divide the molar mass by the empirical formula mass to find the ratio, then multiply the subscripts in the empirical formula by this ratio to get the molecular formula.