Problem 65 - 43 Years JEE ADVANCED (1978-2020) + JEE MAIN Chapterwise & Topicwise Solved Papers Chemistry

Question

The conjugate base of \(\mathrm{HSO}_{4}^{-}\)in aqueous solution is ___ .

Step-by-Step Solution

Answer

The conjugate base of \( \mathrm{HSO}_4^- \) is \( \mathrm{SO}_4^{2-} \).

Step 1: Understanding the concept of acids and bases

An acid is a molecule or ion that can donate a proton ( ext{H}^+), whereas a base is one that can accept a proton. In a conjugate acid-base pair, the acid forms its conjugate base after donating a proton.

Step 2: Identifying the acid in the reaction

In this case, ext{HSO}_4^- is the acid, since it's going to donate a proton to form its conjugate base.

Step 3: Reaction of ext{HSO}_4^- in water (act as acid)

When ext{HSO}_4^- donates a proton ( ext{H}^+), it forms its conjugate base. The reaction can be expressed as: \[ ext{HSO}_4^- ightarrow ext{SO}_4^{2-} + ext{H}^+ \]

Step 4: Identifying the conjugate base formed

From the reaction, we can see that the conjugate base formed after ext{HSO}_4^- loses a proton is ext{SO}_4^{2-}.

Key Concepts

Conjugate Acid-Base Pair

In acid-base chemistry, the concept of conjugate acid-base pairs plays a vital role in understanding reactions. When an acid donates a proton, it transforms into its conjugate base. Let's break this down to get a clearer picture. Suppose you have an acid, like HSO_{4}^{-} , it can release a proton, H^{+} . Once this proton is released, the acid becomes what we call its conjugate base. This change forms a duo, known as a conjugate acid-base pair.

This pairing helps illustrate the proton transfer process and keeps track of which molecules can switch between acting as acids or bases.

The important takeaway here is:

• An acid donates a proton and becomes its conjugate base.
• A base can accept a proton to become its conjugate acid.

Learning how to identify these pairs simplifies the understanding of reaction chains in chemical processes.

Proton Donation

Proton donation is a central idea in the study of acids and bases. An acid is defined by its ability to donate protons, which are hydrogen ions (H^+). When an acid like HSO_{4}^{-} donates a proton, it sets off a chain reaction, creating its conjugate base. But how does this work?

When HSO_{4}^{-} is in water, it can donate an H^{+} ion, transforming itself into SO_{4}^{2-} . This change shows the proton donation action. The proton donation is crucial because it drives the transformation and sets up subsequent reactions that can take place.

Another aspect of proton donation is its impact on pH and reactions in solution:

• Acidic solutions are rich in donated protons (H^+).
• As protons are donated, they can interact with bases, changing the chemical makeup of the solution.

Grasping how proton donation affects reactions helps to predict how acids and bases function in different environments.

Conjugate Base Formation

Understanding how conjugate bases form gives insight into acid-base reactions. When an acid donates a proton, it changes into its conjugate base. For example, when HSO_{4}^{-} donates H^{+} , it becomes SO_{4}^{2-} , which is its conjugate base. Let's explore this:

Initially, HSO_{4}^{-} contains more hydrogen atoms, and after donating an H^{+} , it is left with SO_{4}^{2-} .

Recognizing when and how these conjugate bases form can help predict behavior in reactions:

• Conjugate bases are crucial because they can accept a proton back.
• They play a role in creating buffered solutions, which resist changes in pH.

Forming a conjugate base is more than just a result of proton donation; it is a key part of the reversible reactions that occur in acid-base chemistry. By understanding this process, students can gain a better understanding of the dynamic nature of chemical reactions.