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empirical formula

empirical formula

4.8
The simplest whole number ratio of elements in a chemical compound, not the exact number of atoms
  • noun
  • /ɪmˈpɪrɪkəl ˈfɔrmjələ/
  • Specialized
translation icon : fórmula empírica
  • To calculate the empirical formula of a compound, you need to determine the ratio of each element's atoms.

Examples

  • Chemists often use an empirical formula to express the simplest form of a compound's composition.

  • Re-entrained emission rates were derived by the following empirical formula, where PREFORMATTED TABLE

    Academic text (2002)
  • The empirical formula of water is H2O, which shows the simplest ratio of hydrogen to oxygen.

How Detailed

structural formula
  • Specialized
6.1
chemical formula
  • Specialized
3 3.6
molecular formula
  • Specialized
1 4.1
empirical formula
  • Specialized
4.8

Surface Forms

Morphology

empirical + formula

Although the constituents 'empirical' (based on observation) and 'formula' (a symbolic relation) are individually transparent, the phrase denotes a specific technical chemistry concept — the simplest whole-number ratio of elements — that is not directly derivable from those general meanings. Because this is a domain-specific term whose precise sense requires subject knowledge rather than simple composition, it would be opaque to a B1 learner who only knows the parts.

Etymology

The term empirical formula comes from using real measurements to make a simple recipe showing how many of each element are present in a substance. Empirical means from observation and formula is like a recipe, so the phrase shows the 'simplest whole-number ratio' of elements rather than the 'exact number of atoms'.