Formula Problem

The simplest formula for butane is C2H5 and its molecular mass is about 60. What is the molecular formula of butane?

Solution

First, calculate the sum of the atomic masses for C2H5. Look up the atomic masses for the elements from the Periodic Table . The atomic masses are found to be:

H is

C is

Plugging in these numbers, the sum of the atomic masses for C2H5 is:

2() + 5() =

This means the formula mass of butane is .