AQA GCSE Chemistry (Triple) - Paper 1 Exam-Style Flashcards: Topic 3 - Quantitative Chemistry

These flashcards cover key concepts in Quantitative Chemistry as per the AQA GCSE Chemistry syllabus.

Law of conservation of mass

No atoms are lost or made during a chemical reaction, so the mass of the products equals the mass of the reactants.

Reason for mass change in a reaction

Mass may appear to change if a gas is produced and escapes, or if a gas from the air is used in the reaction.

Relative formula mass (Mr)

The sum of the relative atomic masses (Ar) of all atoms in a formula.

Definition of a mole

One mole contains the same number of particles as there are atoms in 12 g of carbon-12 (Avogadro constant = 6.02 × 10^23).

Formula linking moles, mass, and Mr

Moles = Mass ÷ Mr.

Balanced symbol equation

Shows the ratio of moles of each substance reacting and produced.

Limiting reactant

The reactant that is completely used up first, limiting the amount of product formed.

Concentration in g/dm³

Concentration = Mass of solute ÷ Volume of solution.

Volume of 1 mole of gas at RTP

24 dm³.

End point of a titration

The point at which the reaction is just complete, indicated by a color change.

Percentage yield formula

Percentage yield = (Actual yield ÷ Theoretical yield) × 100.

Atom economy formula

Atom economy = (Mr of desired product ÷ Total Mr of all products) × 100.

Importance of high atom economy

It reduces waste and makes the process more sustainable and cost-effective.