3.1.2
Amount of
Substance
AQA 3.1.2 develops the quantitative language of chemistry. This topic covers relative masses, the mole, Avogadro constant, empirical and molecular formulae, balanced equations, reacting masses, solution concentrations, titration calculations, gas volumes, percentage yield and atom economy.
Revision Notes
Work through each part of AQA 3.1.2 in a structured sequence.
Masses
Relative Masses
Relative atomic mass, relative molecular mass and relative formula mass in terms of carbon-12.
Start revisingAvogadro
The Mole and Avogadro Constant
The mole, Avogadro constant, particles, amount of substance, mass and solution concentration.
Start revisingRatios
Empirical and Molecular Formulae
Empirical formulae, molecular formulae and the relationship between simplest ratio and actual formula.
Start revisingMasses
Chemical Equations and Reacting Masses
Balanced equations, ionic equations and calculations involving masses from chemical equations.
Start revisingCalcs
Concentration and Titration Calculations
Concentration in mol dm⁻³, solution volumes and titration-style amount of substance calculations.
Start revisingEquation
Gas Volumes and the Ideal Gas Equation
Gas volume calculations and use of pV = nRT with variables in SI units.
Start revisingYield
Percentage Yield
Percentage yield calculations from theoretical and actual yield in chemical reactions.
Start revisingEconomy
Atom Economy
Percentage atom economy and the economic, ethical and environmental value of efficient reactions.
Start revising3.1.2 Amount of Substance – AQA A Level Chemistry
The following AQA specification points outline the knowledge and skills students are expected to demonstrate for Amount of Substance.
3.1.2 Amount of Substance
Relative atomic mass and relative molecular mass in terms of 12C.
The term relative formula mass will be used for ionic compounds.
Students should be able to:
The Avogadro constant as the number of particles in a mole.
The mole as applied to electrons, atoms, molecules, ions, formulas and equations.
The concentration of a substance in solution, measured in mol dm-3.
Students should be able to carry out calculations:
Students will not be expected to recall the value of the Avogadro constant.
The ideal gas equation pV = nRT with the variables in SI units.
Students should be able to:
Students will not be expected to recall the value of the gas constant, R.
Empirical formula is the simplest whole number ratio of atoms of each element in a compound.
Molecular formula is the actual number of atoms of each element in a compound.
The relationship between empirical formula and molecular formula.
Students should be able to:
Equations (full and ionic).
Percentage atom economy is: molecular mass of desired product / sum of molecular masses of all reactants x 100
Economic, ethical and environmental advantages for society and for industry of developing chemical processes with a high atom economy.
Students should be able to:
Students should be able to use balanced equations to calculate:
3.1.2 Amount of Substance – AQA A Level Chemistry
The following AQA specification points outline the knowledge and skills students are expected to demonstrate for Amount of Substance.
3.1.2 Amount of Substance
Relative atomic mass and relative molecular mass in terms of 12C.
The term relative formula mass will be used for ionic compounds.
Students should be able to:
The Avogadro constant as the number of particles in a mole.
The mole as applied to electrons, atoms, molecules, ions, formulas and equations.
The concentration of a substance in solution, measured in mol dm-3.
Students should be able to carry out calculations:
Students will not be expected to recall the value of the Avogadro constant.
The ideal gas equation pV = nRT with the variables in SI units.
Students should be able to:
Students will not be expected to recall the value of the gas constant, R.
Empirical formula is the simplest whole number ratio of atoms of each element in a compound.
Molecular formula is the actual number of atoms of each element in a compound.
The relationship between empirical formula and molecular formula.
Students should be able to:
Equations (full and ionic).
Percentage atom economy is: molecular mass of desired product / sum of molecular masses of all reactants x 100
Economic, ethical and environmental advantages for society and for industry of developing chemical processes with a high atom economy.
Students should be able to:
Students should be able to use balanced equations to calculate:
Keep this note — free
Save your progress across every AQA topic. A free account remembers which topics you have covered, saves your question scores, and syncs across your phone and laptop.
- Track every topic you have finished
- Keep your practice-question scores
- No payment, no card, free forever
Already registered? Log in