Conservation of mass
What Conservation of mass means in Chemistry GCSE, as defined for AQA.
Definitions of Conservation of mass
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Reference: AQA
The total mass of reactants equals the total mass of products for a fully balanced equation, as when 4 g plus 32 g gives 36 g.
The total mass of reactants equals the total mass of products, used as a consistency check where all masses are given.
No atoms are lost or made during a chemical reaction, so the mass of the products equals the mass of the reactants.
A balanced equation shows the same number of each type of atom on both sides, so the total mass is conserved.
A final consistency check is that the total mass of reactants equals the total mass of products.
Atoms are rearranged, not destroyed, so atoms are conserved even when the measured mass changes.
Topics that use Conservation of mass
- Amounts of substances in equations (HT only) (AQA GCSE)
- Conservation of mass and balanced chemical equations (AQA GCSE)
- Mass changes when a reactant or product is a gas (AQA GCSE)
- Relative formula mass (AQA GCSE)
- Using moles to balance equations (HT only) (AQA GCSE)
Related terms
- Balanced symbol equations
- Balanced equations and coefficients
- Closed systems and gas exchange
- Coefficient
- Coefficients
- Counting atoms
- Mass relationships in equations
- Molar mass
Using Conservation of mass in the exam
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