empirical & molecular formula

Question 1

how is the table format

Answer 1

element
mass (g)
molar mass (g mol^-1)
no. of moles (mol) (show working)
simplest whole number ratio

Question 2

just some extra notes

Answer 2

number of moles should be 4 to 5 s.f. if it’s an irrational number. the ratio should be whole number

Question 3

if the qn gives percentage compositions instead of mass

Answer 3

‘assume 100g of the compound’ before drawing the table

Question 4

is empirical formula always the same as molecular formula?

Answer 4

no, but they’re not always different either

Question 5

how to find molecular formula from empirical formula and Mr?

Answer 5

Mr from empirical formula =
Let the molecular formula be (AxBy)n
n = Mr / Mr from empirical formula
Molecular formula =