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Limiting Reactants

Reactions stop when one reactant is used up

  • When some magnesium carbonate is placed into a beaker of hydrochloric acid, you can tell a reaction is taking place because you see lots of bubbles of gas being given off

  • After a while, the amount of fizzing slows down

    • The reaction stops when all reactants is used up

    • Reactants that’s used up in called limiting reactants

    • Amount of product formed is directly proportional to amount of limiting reactant

    • Because if you add more reactant there will be more reactant particles, meaning more product particles

The amount of product depends on the limiting reactant

  • You can calculate mass of product formed in a reaction by using the mass of the limiting reactant and the balanced reaction equation

    • Write out the balanced equation

    • Work out relative formula masses

    • Find out how many moles there are of the substance you know the mass of

    • Use balanced equation to work out how many moles there’ll be of the other substance

    • Use the number of moles to calculate the mass

Limiting Reactants

Reactions stop when one reactant is used up

  • When some magnesium carbonate is placed into a beaker of hydrochloric acid, you can tell a reaction is taking place because you see lots of bubbles of gas being given off

  • After a while, the amount of fizzing slows down

    • The reaction stops when all reactants is used up

    • Reactants that’s used up in called limiting reactants

    • Amount of product formed is directly proportional to amount of limiting reactant

    • Because if you add more reactant there will be more reactant particles, meaning more product particles

The amount of product depends on the limiting reactant

  • You can calculate mass of product formed in a reaction by using the mass of the limiting reactant and the balanced reaction equation

    • Write out the balanced equation

    • Work out relative formula masses

    • Find out how many moles there are of the substance you know the mass of

    • Use balanced equation to work out how many moles there’ll be of the other substance

    • Use the number of moles to calculate the mass

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