Chemistry
Notes: Molecular Formula
Empirical formula:
Molecular formula:
Example:
Compound A
Compound B
Formula
Empirical/Molecular?
How to find Molecular Formula
Example #1: The simplest formula for butane is C2H5 and its molecular mass is 60g/mol. What is the molecular formula
of butane?
1.
2.
3.
4.
Examples:
1. The simplest formula for vitamin C is C3H4O3. Experimental data indicates that the molecular mass of vitamin C
is about 180 g/mol. What is the molecular formula of vitamin C?
2.
A compound contains 18.8% sodium, 29% chlorine, and 52.2% oxygen, by mass. If the molar mass of the
compound in 122.44 g/mol, determine the empirical and molecular formulas.
3.
Caffeine has an elemental analysis of 49.48% carbon, 5.190% hydrogen, 16.47% oxygen, and 28.85% nitrogen.
It has a molar mass of 194.19 g/mol. What is the molecular formula of caffeine?