What is the molecular formula of a substance that has an empirical formula of C2H5 and a molecular mass of 58 g/mole?

1 Answer
Nov 14, 2015

The empirical formula is always a multiple of the empirical formula, but remember the multiple may be #1#.

Explanation:

So #MF=(EF)xxn#. Thus #[2xx12.011*g*mol^(-1)+ 5xx1.00794*g*mol^(-1)]xxn=58*g*mol^(-1).#

It does not take much algebra to find that #n# #=# #2#.

Thus the molecular formula #=# #2xxC_2H_5# #=# #C_4H_10#, butane.