So they can tell what exact species it is.
Given :
A compound has a molar mass of 129 g/mol .
Empirical formula of compound is C₂H₅N .
To Find :
The molecular formula of the compound.
Solution :
Empirical mass of compound :

Now, n-factor is :

Multiplying each atom in the formula by 3 , we get :
Molecular Formula, C₆H₁₅N₃
We would use miles to measure the diameter of the earth because that is the greatest measure of length that is possible to measure something large.
I’m not sure what the answer is but I hope someone can help you