Question

Reaction intermediates are formed during the reaction but are not shown in the overall reaction. They are important to a multistep reaction. Which of the following statements about intermediates is TRUE?

A
Intermediates can be formed and held in that state indefinitely due to the stable nature of the intermediate species.
B
Intermediates are sometimes formed in simple, one-step reaction mechanisms.
C
An intermediate is formed in one step of a multistep mechanism and then used completely in a subsequent elementary step.
D
An intermediate formed in a biological system is very different in function than one formed in a nonbiological system.

Answer 1

The true statement about reaction intermediates is C: An intermediate is formed in one step of a multistep mechanism and then consumed in a subsequent elementary step. Intermediates are transient species not present in the overall balanced equation.

Step-by-step explanation:

Among the statements provided regarding reaction intermediates, statement C is TRUE. An intermediate is a species that is created in one step of a multistep reaction mechanism and consumed in a subsequent step. This means that while intermediates are crucial for the progression of the reaction, they are not found in the overall balanced chemical equation because they are not present in the reaction's initial or final states.

Intermediates are by their nature transient, and they do not have an indefinite lifespan in a reaction system. In contrast to statement A, they are generally unstable and exist only for a brief period during a reaction. Statement B is incorrect because intermediates are characteristic of complex reactions rather than simple, one-step reactions. Lastly, statement D is incorrect because the functional distinction of an intermediate does not depend on whether the system is biological or nonbiological; its role within a reaction mechanism is similar regardless of the context.