BRAINCAKECalculations
The mass of a sample of substance can be used to count the number of atoms in the sample by using the formula moles = mass &div Mr
where Mr is the relative atomic mass or relative molecular mass or relative formula mass of the substance.
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Key terms in this lesson
- mole
- The amount of substance containing 6.02 x 10^23 particles, the same number as the atoms in 12 g of carbon-12.
- relative atomic mass
- The weighted mean mass of one atom of an element compared with 1/12 of the mass of one atom of carbon-12.
- relative molecular mass
- The sum of the relative atomic masses of the atoms in a molecule's formula, compared with 1/12 the mass of carbon-12.
More in Amount of Substance and Calculations
- Counting Atoms - The Mole
- Chemical Formulae
- Balanced Equations
- Ionic Equations
- Ionic Equations - Question1
- Ionic Equations - Question 2
- Ionic Equations - Question3
- Ionic Equations - Question 4
All 39 lessons in Amount of Substance and Calculations · All Edexcel AS-level Chemistry topics