Final answer:
The activation energy of a reaction decreases by 30 kJ/mol in the presence of a catalyst, while the rate remains unchanged. The activation energy for the catalyzed reaction is 30 kJ/mol less than the activation energy for the uncatalyzed reaction.
Step-by-step explanation:
The activation energy (Ea) of a reaction is the minimum energy required for the reaction to occur. In the presence of a catalyst, the activation energy decreases by 30 kJ/mol. If the rate of the reaction remains unchanged, it means that the catalyzed reaction has a higher rate constant, which is related to the activation energy.
According to the Arrhenius equation, the rate constant (k) is equal to the pre-exponential factor (A) multiplied by the exponential term (-Ea/RT), where R is the ideal gas constant and T is the temperature in Kelvin.
Since the rate remains unchanged, the exponential term must stay the same. Therefore, the activation energy for the catalyzed reaction is 30 kJ/mol less than the activation energy for the uncatalyzed reaction.
Learn more about Activation energy