Final answer:
The rate of a chemical reaction and its activation energy are inversely proportional, with a high activation energy leading to a slower reaction and low activation energy to a faster rate. Option d) is the correct answer, which reflects this inverse relationship.
Step-by-step explanation:
The relationship between the rate of a reaction and its activation energy is a fundamental concept in chemistry that helps us understand how chemical reactions occur. The activation energy, denoted as Ea, is the minimum energy that must be provided for reactants to transform into products. If the activation energy is high, the reactants need to gain a significant amount of energy to overcome this barrier, making the reaction slower. Conversely, if the activation energy is lower, more molecules possess the requisite energy to react, leading to a faster reaction rate. Therefore, the correct answer is d) Activation energy and reaction rate are inversely proportional.
As an illustration, the rusting of iron is a slow process due to its high activation energy. On the other hand, when fuels burn, they initially require a spark to provide the necessary activation energy but, once burning, continue to release heat that sustains the reaction by providing the activation energy to surrounding fuel molecules. In biology, most cellular reactions require the assistance of enzymes to lower the activation energy to a level where the rate of reactions is efficient for cell survival.
Overall, understanding activation energy is essential in predicting and controlling the rate of chemical reactions, whether in industrial processes, biological systems, or everyday occurrences like the burning of a candle.