2.4- EMPIRICAL AND MOLECULAR FORMULAE

Question 1

What is the empirical formula?

Answer 1

formula that represents the simplest whole number ratio of atoms of each element present in a compound

Question 2

How to work out the empirical formula? (3)

Answer 2

find masses of each of the elements present in compound

work out no. of moles of atoms of each element
no. of moles = mass of element / mass of 1 mol of element

convert number of moles of each element into whole number ratio

Question 3

What does the molecular formula give?

Answer 3

actual number of atoms of each element in one molecule of compound

Question 4

Is the empirical formula always the same as the molecular formula?

Answer 4

no

Question 5

How do you find the number of units of the empirical formula in the molecular formula?

Answer 5

divide the relative molecular mass by the relative mass of the empirical formula