Which of the following statements concerning catalysts is false?
a) Catalysts may be solid, if the reactants are gaseous
b) Catalysts may be used up, but are always regenerated
c) Catalysts speed up reactions that would otherwise take years
d) Catalysts raise the activation energy of a reaction
e) Catalysts increase the number of effective collisions
d) Catalysts raise the activation energy of a reaction
Catalysts lower the activation energy of a reaction, making it easier for the reaction to occur. Therefore, statement d) is false.
what is the final and correct answer?
The correct answer is:
d) Catalysts lower the activation energy of a reaction
To determine which of the following statements concerning catalysts is false, let's examine each statement:
a) Catalysts may be solid if the reactants are gaseous.
Explanation: This statement is true. Catalysts can be in different states of matter depending on the state of the reactants.
b) Catalysts may be used up but are always regenerated.
Explanation: This statement is true. Catalysts provide an alternative reaction pathway but are not consumed in the reaction and can be used repeatedly.
c) Catalysts speed up reactions that would otherwise take years.
Explanation: This statement is true. Catalysts lower the activation energy barrier, which allows reactions to occur more quickly, even though they might be slow or energetically unfavorable under normal conditions.
d) Catalysts raise the activation energy of a reaction.
Explanation: This statement is false. Catalysts actually lower the activation energy, making it easier for reactants to convert into products.
e) Catalysts increase the number of effective collisions.
Explanation: This statement is true. Catalysts provide a surface for reactant molecules to adsorb onto, increasing the chances of collisions and successful reactions.
Therefore, the statement that is false is d) Catalysts raise the activation energy of a reaction.