Question

What is the molecular formula if the empirical formula is `C_3H_7`, and the experimental molar mass is 86 g/mole?

Answer 1

`C_6H_14`

Explanation:

Brute force method:

1. find molar mass of the empirical formula you are given
2. set it equal to 86g/mol
3. multiply it until you get 86g/mol

in this case:
C=12.01
N=14
H=1.008

the empirical formula adds up to 43g/mol
multiply by two, we get 86g/mol