Question

Write the formula of the conjugate acid for each of the following: a. \(\mathrm{SO}_{4}^{2-}\) b. \(\mathrm{CN}^{-}\) c. \(\mathrm{OH}^{-}\) d. \(\mathrm{ClO}_{2}^{-}\)

Short answer

a. \( \text{HSO}_4^{-} \); b. \( \text{HCN} \); c. \( \text{H}_2\text{O} \); d. \( \text{HClO}_2 \)

Step-by-step solution

Identify the Base

Determine the original base for each of the given species. In this case, the given species are: a. \(\text{SO}_4^{2-}\) b. \(\text{CN}^{-}\) c. \(\text{OH}^{-}\) d. \(\text{ClO}_2^{-}\)

Add a Proton (H⁺) to Each Base

To find the conjugate acid of each base, add one proton (H⁺) to each species. This will increase the species' charge by +1. a. For \(\text{SO}_4^{2-}\), adding H⁺ produces \( \text{HSO}_4^{-} \). b. For \(\text{CN}^{-}\), adding H⁺ produces \( \text{HCN} \). c. For \(\text{OH}^{-}\), adding H⁺ produces \( \text{H}_2\text{O} \). d. For \(\text{ClO}_2^{-}\), adding H⁺ produces \( \text{HClO}_2 \).

Write the Resulting Conjugate Acids

Now that each base has had a proton added to it, the results are: a. \( \text{HSO}_4^{-} \) b. \( \text{HCN} \) c. \( \text{H}_2\text{O} \) d. \( \text{HClO}_2 \)

Key concepts

acid-base reactions

Understanding **acid-base reactions** is crucial in chemistry. These reactions involve the transfer of protons (H⁺) from one chemical species to another. According to the Bronsted-Lowry theory, acids are proton donors while bases are proton acceptors. When an acid loses a proton, it forms its conjugate base. Conversely, when a base gains a proton, it forms its conjugate acid. This concept is fundamental to solving problems like identifying the conjugate acids of given bases.

proton transfer

At the heart of amino acid reactions is the **proton transfer** process. A proton transfer involves moving a hydrogen ion (H⁺) from one molecule to another. This simple act can significantly change the properties and behaviors of the involved molecules. To identify the conjugate acid, you take a base and add one proton. This alters its charge by +1. For example, adding H⁺ to \( \text{OH}^{-} \) turns it into \( \text{H}_2\text{O} \). Each original base in the exercise undergoes the same transformation process to give its conjugate acid.

chemical species

In chemistry, **chemical species** are entities such as atoms, molecules, ions, and radicals distinguished by their structure and chemical composition. Each species can participate in reactions in unique ways. For example, \( \text{SO}_4^{2-} \), \( \text{CN}^{-} \), \( \text{OH}^{-} \), and \( \text{ClO}_2^{-} \) are all distinct species with different behaviors in acid-base reactions. Identifying the conjugate acids requires understanding how each chemical species can accept a proton (H⁺) and transform into a new species with a different charge and structure.