Free Empirical Formula Calculator

Find the mole ratio of two elements from their mass percentages to determine the simplest formula ratio.

g
g/mol
g
g/mol

Ratio of A (divide by smallest)

1.00

Moles of A3.3303 mol
Moles of B6.6468 mol
Ratio of B (divide by smallest)2.00

Ratio of A (divide by smallest) vs Mass of Element A

How to Find the Empirical Formula

Steps

1. Convert mass of each element to moles: moles = mass / atomic mass 2. Divide each by the smallest number of moles 3. Round to the nearest whole number to get subscripts

Example Calculation

A compound has 40 g C and 6.7 g H.

  1. 01Moles C = 40 / 12.011 = 3.33
  2. 02Moles H = 6.7 / 1.008 = 6.65
  3. 03Divide by smallest (3.33): C = 1, H = 2
  4. 04Empirical formula: CH2

Frequently Asked Questions

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Learn what molarity is, how to calculate it, and why it matters in chemistry. Covers moles, liters, dilution, and step-by-step examples for preparing solutions.

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