What is the difference between the #"molecular and empirical formulae?"#

1 Answer
anor277
Nov 27, 2016

The difference between an empirical formula mass and a molecular mass.........? See here and links.

Explanation:

The difference is a whole number multiple.

The molecular formula is always a whole number multiple of the empirical formula. Take a simple molecule such as #"ethane, " H_3C-CH_3#. The empirical formula is the simplest whole number multiple tha represents the atomic proportion of this formula, i.e. #CH_3#.

And given that #"molecular formula"# #=# #nxx"empirical formula"#, in this case #n=2#.

Typically, an analyst can give you a percentage composition of your compound; i.e. #%C, H, N#; this gives an empirical formula by standard means. And then this empirical formula is converted to a molcular formula if some way of assessing the molecular mass (i.e. mass spec., boiling point elevation) can be found.

Related questions
See all questions in Empirical and Molecular Formulas
Impact of this question
3856 views around the world
You can reuse this answer
Creative Commons License