C5

Question 1

How do you calculate the empirical formula with masses/percentages?

Answer 1

1) List all elements in the compound
2) Underneath them, write their experimental masses or percentages
3) Divide each mass/percentage by the Atomic Mass (Ar) for that particular element
4) Convert them into the simplest possible ratio
4) Write out the empirical formula using the simplest ratio

Question 2

What is the empirical formula of this hydrocarbon (80% Carbon, 20% Hydrogen)

Answer 2

Carbon   :   Hydrogen
     80%   :   20%
 (80/12)   :   (20/1)
          1    :   3
= CH3