Arrange the following substances in order of increasing strength ...

Question

Arrange the following substances in order of increasing strength as an oxidizing agent, and account for the trend. (a) Cr2+ (b) Cr3+ (c) Cr2O72-

Accepted Answer

Step 1: Understand the concept of an oxidizing agent. An oxidizing agent is a substance that gains electrons in a chemical reaction and is reduced in the process. The strength of an oxidizing agent is determined by its ability to accept electrons.. Step 2: Consider the oxidation states of chromium in each species. For Cr^{2+}, the oxidation state is +2; for Cr^{3+}, it is +3; and for Cr_2O_7^{2-}, it is +6.. Step 3: Recognize that a higher oxidation state generally indicates a stronger oxidizing agent because it has a greater tendency to gain electrons to be reduced to a lower oxidation state.. Step 4: Compare the oxidation states: Cr_2O_7^{2-} has the highest oxidation state (+6), followed by Cr^{3+} (+3), and then Cr^{2+} (+2). Therefore, Cr_2O_7^{2-} is expected to be the strongest oxidizing agent.. Step 5: Arrange the substances in order of increasing strength as an oxidizing agent: Cr^{2+} < Cr^{3+} < Cr_2O_7^{2-}. This order is based on their ability to gain electrons and be reduced.

Arrange the following substances in order of increasing strength as an oxidizing agent, and account for the trend. (a) Cr2+ (b) Cr3+ (c) Cr2O72-

Key Concepts

Oxidizing Agents

Oxidation States

Chromate Ion (Cr2O72-)