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Chemistry

Mass, moles and particle count

Convert mass into an amount in moles and a particle count using the appropriate molar mass.

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01

Your inputs

The starting values are an example.

Use a value that matches the substance and particle type; 18 g/mol is a simplified example.

Decimals: 12.5 · Thousands: 1,234.56. Follow the field instructions for lists.

02

Your result

Enter your values and select Calculate.

Your calculation will appear here.

Your result will include the relevant values and units.

Understand the calculation

Formula and example

How it is calculated

n = m/M; N = n × Nₐ; Nₐ = 6.02214076 × 10²³ mol⁻¹

Worked example

18 g of a substance with a molar mass of 18 g/mol equals 1 mol and 6.02214076 × 10²³ particles.

Things to check

  • The particle type matters: a molecule and its individual atoms are different counted entities.
  • The Avogadro constant is defined exactly in the SI. The precision of the mass and molar mass is still limited.

Sources and references