Relative formula mass and the moleReading · 0%
Balancing equations and stoichiometry1 h 45 min of study
Empirical formulae, molecular formulae and percentage composition1 h 30 min of study
Reacting masses, limiting reactants, yield and atom economy2 h of study
Concentration, titration and solution calculations2 h of study
Gas volumes and gas stoichiometry1 h 15 min of study

This unit is ≈17% of the GCSE Chemistry, across 6 lessons. Full syllabus

Lesson 1 of 6 · Quantitative chemistry

Relative formula mass and the mole

3 quick checks≈3% of the testCore: Core: tested on most papers

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By the end you’ll be able to

define relative atomic mass ($A_r$) and relative formula mass ($M_r$) and calculate $M_r$ from a chemical formula using given atomic masses
define the mole as the amount of substance containing the Avogadro constant number of entities and use $N_A = 6.02 \times 10^{23}\ \text{mol}^{-1}$ where required
calculate the amount of substance in moles from mass and molar mass using $n = \dfrac{m}{M}$

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Adaptive questions on relative formula mass and the mole.

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calculate mass from amount of substance using $m = nM$

calculate the number of atoms, molecules, ions or formula units from moles, and calculate moles from a given number of particles

interpret chemical formulae in terms of numbers and ratios of atoms or ions present

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