The empirical formula of butadiene is #C_2H_3#. An experimental determination of the molar mass of butadiene yields the value of 54 g/mol. What is the molecular formula of butadiene?

1 Answer
Jan 15, 2016

#C_4H_6#

Explanation:

The molecular formula is always a mulitple of the empirical formula; of course the multiple may be one if the molecular formula is the same as the empirical formula.

Given that #"MF"# #=# #("EF")_n#, we simply solve for #n# using the sum of the constituent atomic masses:

#nxx(2xx12.011 + 3xx1.00794)*g*mol^-1# #=# #54# #g*mol^-1#

Clearly #n# #=# #2#.

Molecular formula #=# #2xxC_2H_3# #=# #C_29H_37??#