Question

Isooctane has the molecular formula C8H18. What is its empirical formula

Answer 1

GOSH I feel the pain.
Finding the empirical formula starting from the molecular formula is pretty much finding a least common factor for the subscripts. 8 and 18 can both reduce by two, making it C4H9.

Answer 2

Its empirical formula is
`C_(4)H_(9)`

Step-by-step explanation:

The empirical formula of a compound has the relative number of atoms in the molecule, expressed in the simplest whole-number ratios.

We know that the molecular formula of Isooctane is :

`C_(8)H_(18)`

If we want to obtain the empirical formula we need to simplify the numbers ''8'' and ''18'' to obtain the simplest whole-number ratios.

If we do this, we find that ''8'' can be simplified by 8,4,2 or 1.

The number ''18'' can be simplified by 18,9,6,3 or 1.

The highest number which is common to ''8'' and ''18'' is the number 2.

If we simplify the molecular formula of Isooctane by 2 ⇒

`C_(8)H_(18)` ⇒
`C_(4)H_(9)`

The empirical formula of Isooctane is
`C_(4)H_(9)`