An empirical formula can be calculated from information about the mass of each element in a compound or from the percentage composition.
Explanation:
The simplest whole-number ratio of each type of atom in a compound is the empirical formula of a compound. For percent composition, we assume the total percent of a compound is equal to 100%. If a compound containing 68% carbon, 9% hydrogen, and 23% oxygen, we would assume 68 grams of carbon, 9 grams of hydrogen, and 23 grams of oxygen.
The steps to calculate the empirical formula of a compound are as follows:
Step 1: The mass of each element present in grams is calculated .
Element % = mass in gram
Step 2: The number of moles of each type of atom present is determined.
m/atomic mass = Molar amount (M)
Step 3: The number of moles of each element is divided by the smallest number.
Molar amount / least M value = Atomic Ratio (R)
Step 4: Convert the numbers into whole numbers. This set of whole numbers are the empirical formula of a compound.
R * whole number = Empirical Formula
