Empirical Formula Chemistry Example 1

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Example 1

medium
A compound contains 40.0%40.0\% C, 6.7%6.7\% H, and 53.3%53.3\% O by mass. Determine the empirical formula.

Solution

  1. 1
    Assume 100100 g: C = 40.040.0 g, H = 6.76.7 g, O = 53.353.3 g.
  2. 2
    Convert to moles: C = 40.012.01=3.33\frac{40.0}{12.01} = 3.33, H = 6.71.008=6.65\frac{6.7}{1.008} = 6.65, O = 53.316.00=3.33\frac{53.3}{16.00} = 3.33.
  3. 3
    Divide by smallest (3.33): C = 1, H = 2, O = 1.
  4. 4
    Empirical formula: CH2O\text{CH}_2\text{O}.

Answer

CH2O\text{CH}_2\text{O}
The empirical formula represents the simplest whole-number ratio of atoms. The molecular formula may be a multiple of the empirical formula (e.g., glucose C6H12O6\text{C}_6\text{H}_{12}\text{O}_6 has the same empirical formula CH2O\text{CH}_2\text{O}).

About Empirical Formula

The chemical formula that shows the simplest whole-number ratio of atoms of each element present in a compound, obtained by dividing all subscripts by their.

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More Empirical Formula Examples

Example 2 hard

A compound has empirical formula [formula] and a molar mass of [formula]. Find the molecular formula

Example 3 medium

A compound is [formula] Mg and [formula] N. Find the empirical formula.

Example 4 medium

A compound is [formula] carbon, [formula] hydrogen, and [formula] oxygen by mass. What is its empiri

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