which of the following is a characteristic of a catalyst?
a...can convert an endothermic to an exothermic reaction
b...raises the EA
c...raises the energy of the reactant(s)
d...is recovered unchanged after completion of the reaction
To determine which of the following is a characteristic of a catalyst, let's analyze each option and find the answer:
a) Can convert an endothermic to an exothermic reaction: A catalyst does not alter the thermodynamics or the nature of a reaction; it only speeds up the rate of the reaction. Therefore, it does not have the ability to convert an endothermic to an exothermic reaction.
b) Raises the EA (activation energy): A catalyst actually lowers the activation energy of a reaction, allowing it to proceed at a faster rate. So, this option is incorrect.
c) Raises the energy of the reactant(s): Catalysts generally lower the energy barriers for the reaction to occur, which means they lower the energy of the transition state or the activated complex. Therefore, this option is incorrect.
d) Is recovered unchanged after completion of the reaction: This is a characteristic of a catalyst. A catalyst provides an alternative reaction pathway that lowers the activation energy, but it remains unchanged chemically and is recovered after the reaction is completed. Therefore, this is the correct option.
So, the correct answer is option d) is recovered unchanged after completion of the reaction.