Conservation of mass
AQA GCSE Chemistry calculation · part of the free Calculation Climb
In a reaction no atoms are created or destroyed, so the total mass of reactants = total mass of products. Use it to find a missing mass.
How to do it — step by step
- Add up the masses you know on each side.
- The missing mass is whatever makes both sides equal.
Worked example
10 g of calcium carbonate → calcium oxide + 4.4 g of carbon dioxide.
Mass of calcium oxide = 10 − 4.4 = 5.6 g
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