To answer questions 13–15, refer to the mechanism: H2O21aq2 + I-1aq2¡OH-1aq2 + HOI1aq2 Slower, rate-determining HOI1aq2 + I-1aq2¡OH-1aq2 + I21aq2 Faster 2 OH-1aq2 + 2 H3O+1aq2¡4 H2O1l2 Faster Identify the catalyst and intermediate(s) in the mechanism. (LO 14.12, 14.16) (a) Catalyst = I-, intermediates = OH-, HOI (b) Catalyst = H3O+, intermediate = HOI (c) No catalyst, intermediate = I2 (d) No catalyst, intermediates = OH-, HOI

Verified step by step guidance

1. insert step 1: Understand the role of a catalyst and an intermediate in a chemical reaction. A catalyst is a substance that increases the rate of a reaction without being consumed, while an intermediate is a species that is formed and consumed during the reaction.
2. insert step 2: Analyze the given reaction mechanism. The mechanism consists of three steps, with the first step being the slow, rate-determining step.
3. insert step 3: Identify the species that appear in the mechanism but are not present in the overall balanced equation. These species are typically intermediates.
4. insert step 4: Look for a species that is present at the beginning and end of the reaction mechanism but does not appear in the overall balanced equation. This species is likely the catalyst.
5. insert step 5: Compare your findings with the given options (a, b, c, d) to determine which option correctly identifies the catalyst and intermediates.

Key Concepts

Catalysts

A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. It provides an alternative pathway for the reaction with a lower activation energy. In the context of reaction mechanisms, identifying the catalyst is crucial as it helps to understand how the reaction can proceed more efficiently.

Intermediates

Intermediates are species that are formed during the reaction but are not present in the final products. They are typically unstable and exist only for a short duration. Recognizing intermediates is essential for understanding the stepwise progression of a reaction mechanism and how reactants transform into products.

Reaction Mechanism

A reaction mechanism is a detailed description of the steps involved in a chemical reaction, including the sequence of elementary reactions. It outlines how reactants are converted into products, highlighting the role of catalysts and intermediates. Analyzing the mechanism allows chemists to predict the behavior of the reaction under various conditions.