Question

What can you say about the empirical and molecular formula and how do you understand the
method of arriving molecular formula from empirical formula.

Answer 1

empirical formula is the simplest formula of a compound which gives the simple whole number ratio of the various elements present in one molecule of a substance
molecular formula is the chemical formula of a compound which gives the exact number of atoms of the various elements present in one molecule of it

1. calculate the empirical formula mass
2. calculate the molecular formula of the compound 
    molecular formula= 2 X Vapour Density
3. calculate n
   n= molecular formula mass/ empirical formula mass
4. molecular formula= n(empirical formula)