The empirical formula of a compound is CH2. Its molecular mass is 70 g mol what is its molecular formula?

1 Answer
Oliver S.
Feb 26, 2018

#C_5H_10#

Explanation:

In order to find the molecular formula from an empirical formula you must find the ratio of their molecular masses.

We know that the molecular mass of the molecule is 70 #gmol^-1#. We can calculate the molar mass of #CH_2# from the periodic table:
C=12.01 #gmol^-1#
H=1.01 #gmol^-1#
#CH_2#=14.03 #gmol^-1#

Hence we can find the ratio:
#(14.03)/(70) approx 0.2#
That means we must multiply all the molecules by 5 in #CH_2# to reach the desired molar mass.
Hence: #C_(5)H_(5 times 2)#= #C_5H_10#

Related questions
Impact of this question
44754 views around the world
You can reuse this answer
Creative Commons License