is the empirical formula the same as molecular formula??

  • 0 votes

does anyone know whether the empirical and molecular formulae are the same thing or not..

thaks :)

Posted Fri 18th May, 2012 @ 11:37 by Muzz :P

2 Answers

  • 1 vote

No. In some cases yes but majority of the times it is no. The empirical formula is smallest ratio between atoms in a compound and the molecular formula is what the actual formula for the compound for example if I had a hydrocarbon like ethene with the molecular formula C2H4 has the empirical, formula of CH2 ==> as you can see that the 2 can cancel out in both the carbon and the hydrogen.

In some cases it doesnt fit this for example propane with the molecular formula C3H8 cant be reduced any further.

Rule 1: for all alkenes the emperical formula is always CH2

Rule 2: Only in sum cases in alkanes !!! can the molecular formula be  the same as the empirical

Answered Fri 18th May, 2012 @ 11:57 by Braniac
  • 0 votes

ok thanks for that so does that mean that you would have to use different methods in order to work out the empirical formula and the molecular formula??

Answered Fri 18th May, 2012 @ 12:21 by Muzz :P