What is the limiting reactant in a reaction?
The reactant that runs out first, limiting the amount of product that can form.
AQA GCSE Combined Science: Trilogy (8464) — Chemistry — Higher · 5.3.2.4
Revise AQA GCSE Combined Science: Trilogy (8464) — Chemistry — Higher specification point 5.3.2.4, Limiting reactants (HT only), with free active-recall flashcards. Flip through the set or review every question and answer below.
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What is the limiting reactant in a reaction?
The reactant that runs out first, limiting the amount of product that can form.
How do you identify the limiting reactant from given reactant amounts?
Convert any masses to moles, then compare the reactant amounts with the stoichiometric ratio in the balanced equation. The reactant with too few moles relative to that ratio is limiting.
Which reactant is used to calculate the maximum possible product amount?
The limiting reactant, not the reactant in excess.
What do chemical equations show about the mole ratios in which reactants combine?
Reactants combine in fixed mole ratios.
What is the limiting reactant?
The reactant that is completely used up first.
Why does the limiting reactant limit the amount of product formed?
Once it is consumed, no more product can form, even if another reactant remains.
What is an excess reactant?
A reactant supplied in more than the required amount.
Why might one reactant be supplied in excess?
To ensure that the other reactant is fully used up.