Empirical and molecular formula

Question 1

What is the empirical formula?

Answer 1

The smallest whole number ratio of atoms of each element in a compound.

Question 2

What is the molecular formula?

Answer 2

The actual number of atom is of each type of element in a molecule.

Question 3

What are the steps to finding the empirical formula?

Answer 3

• Find the moles from the given element/ compound given with a mass
• Find the other moles
• Divide by smallest ratio

Question 4

What are the steps to find the empirical formula when given percentages?

Answer 4

• Divide each % by the relative mass (Mr)
• Divide each number of moles by the smallest number
• Use the ratio to work out the empirical formula