Empirical and molecular formulae Flashcards
What is the empirical formula?
the formula that represents the simplest whole number ratio of the atoms of each element present in a compound
How do you find the empirical formula?
1) find the masses of each elements present in a compound
2) work out the number of moles of atoms of each element
n = m /m of 1mol
3) convert the number of moles of each element into a whole number ratio
How do you find the simplest ratio?
divide each number by the smallest number
What is the molecular formula?
gives the actual number of atoms of each element in one molecule
it applies only to substances that exicst as molecules
How do you find the number of units of the empirical formula in the molecular formula?
divide the relative molecular mass by the relative mass of the empirical formular