Question

In a previous problem, the empirical formula of a compound of phosphorus and oxygen was found to be p2o5. experimentation shows that the molar mass of this compound is 283.89g/mol. what is the compounds molecular formula?

Answer 1

The empirical formula for the compound is - P₂O₅
the empirical formula is the simplest ratio of whole numbers of components in a compound.
molecular formula is the actual ratio of components in a compound.
we have to first find the number of empirical units in the molecular formula 
molecular mass - 283.89 g/mol
mass of empirical formula - 283.8 g
number of empirical units - 283.89 g/mol / 283.8 g
number of empirical units - 1.000 
therefore empirical formula = molecular formula 
molecular formula - P₂O₅