When a reaction is catalyzed:
a) Is the catalyst involved in the reaction? (State your evidence)
b) Has the catalyst been consumed when the reaction is complete?
a) Yes, you can probably tell because the activation energy gets lower and thus allow the reaction to speed up way faster than without a catalyst... it's kind of dumb to ask if in catalyst is involved in a CATALYZED reaction...
b) No, the catalyst will get recycled at the end of the reaction.
a)Yes, the catalyst enters into the reaction.
b) Although the catalyst enters into the reaction, it is regenerated in a subsequent step; the net effect is that none of it is consumed.
Here is a site that gives some examples.
http://en.wikipedia.org/wiki/Catalyst
To determine whether a catalyst is involved in a reaction and whether it is consumed when the reaction is complete, we can look at the following:
a) Is the catalyst involved in the reaction?
To determine if a catalyst is involved in a reaction, one way is to check whether it appears in the overall balanced chemical equation. If the catalyst appears as a reactant, it directly participates in the reaction. On the other hand, if the catalyst does not appear in the balanced equation, it is not directly involved and acts by providing an alternate path with lower activation energy for the reaction to occur.
b) Has the catalyst been consumed when the reaction is complete?
In general, catalysts are not consumed during a chemical reaction. Catalysts facilitate the reaction by providing an alternative pathway with lower activation energy. They accomplish this by forming temporary bonds with reactant molecules, lowering the energy barrier for the reaction to occur. At the end of the reaction, the catalyst can be recovered unchanged and can be reused in subsequent reactions.
However, there may be rare cases where a catalyst is partially consumed or transformed during the reaction. This typically occurs in reactions involving heterogeneous catalysts, where the catalyst is present in a different phase (e.g., a solid catalyst in a liquid-gas reaction). In such cases, the catalyst may undergo surface changes and get deactivated over time. Nevertheless, even if the catalyst undergoes some changes, it is usually not fully consumed or destroyed.
In summary, a catalyst can be involved in a reaction either by directly participating in the reaction or by facilitating it without being consumed.