Empirical Formula Calculator

Calculate Empirical Formula











Formula

The steps to calculate the empirical formula are:

  1. Convert the mass of each element to moles using the atomic masses from the periodic table.
  2. Divide the moles of each element by the smallest number of moles calculated.
  3. Round to the nearest whole number to find the atom ratio, which represents the empirical formula.

Example

Let's say we have a compound with 40.92 g of carbon, 4.58 g of hydrogen, and 54.50 g of oxygen. Using the atomic masses (C: 12.01, H: 1.008, O: 16.00):

\[ \text{Moles of C} = \frac{40.92}{12.01} \approx 3.41 \]

\[ \text{Moles of H} = \frac{4.58}{1.008} \approx 4.54 \]

\[ \text{Moles of O} = \frac{54.50}{16.00} \approx 3.41 \]

Divide by the smallest number of moles (3.41):

\[ \text{Ratio of C} = \frac{3.41}{3.41} = 1 \]

\[ \text{Ratio of H} = \frac{4.54}{3.41} \approx 1.33 \approx 4 \]

\[ \text{Ratio of O} = \frac{3.41}{3.41} = 1 \]

So, the empirical formula is \( \text{C}_1\text{H}_4\text{O}_1 \) or simply \( \text{CH}_4\text{O} \).

What is the Empirical Formula?

The empirical formula of a compound is the simplest whole-number ratio of atoms of each element in the compound. It provides the relative number of atoms of each element in the compound.