What is a catalyst?
A substance that changes a reaction’s rate, usually increasing it, without being consumed overall; it remains chemically unchanged at the end.
AQA GCSE Combined Science: Trilogy (8464) — Chemistry — Foundation · 5.6.1.4
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What is a catalyst?
A substance that changes a reaction’s rate, usually increasing it, without being consumed overall; it remains chemically unchanged at the end.
Why is a catalyst not written as a reactant or product in a balanced chemical equation?
Because it is not consumed overall.
What does it mean that catalysts are specific?
A catalyst that works for one reaction may not work for another.
What role do enzymes play in living organisms?
They act as catalysts that speed up chemical reactions.
How does a catalyst change the pathway of a reaction?
It provides an alternative pathway with a lower activation energy.
Why does a lower activation energy make a reaction faster?
A greater proportion of particle collisions have enough energy for the reaction to occur each second.
How does a catalysed reaction appear on a reaction profile compared with the uncatalysed reaction?
It has a lower energy peak.
How does a catalyst affect the overall energy change of a reaction?
It stays the same: the catalyst changes the pathway, not the reactants or products.