The acid that results when a base accepts a proton is called

Options

A. Conjugate base of the acid
B. Conjugate protonated base
C. Lewis base
D. Conjugate acid of the base

Answer

To solve the question, "The acid that results when a base accepts a proton is called," we need to understand the concepts of acids and bases, particularly in the context of the Brønsted-Lowry theory.

### Step-by-Step Solution:

1. **Understanding Acids and Bases**:
- According to the Brønsted-Lowry theory, an acid is defined as a substance that donates a proton (H⁺), while a base is defined as a substance that accepts a proton.

2. **Identifying the Process**:
- When a base accepts a proton (H⁺), it transforms into a new species. This new species is what we are interested in identifying.

3. **Defining the Resulting Acid**:
- The acid that forms when a base accepts a proton is specifically referred to as the "conjugate acid" of that base.

4. **Examples for Clarity**:
- For instance, if we take the base H₂PO₄⁻ (dihydrogen phosphate), when it accepts a proton (H⁺), it becomes H₃PO₄ (phosphoric acid). Here, H₃PO₄ is the conjugate acid of the base H₂PO₄⁻.
- Another example is if we have the base HB⁻ (where B represents a base), upon accepting a proton, it becomes H₂B (the conjugate acid).

5. **Conclusion**:
- Therefore, the acid that results when a base accepts a proton is called the "conjugate acid."

### Final Answer:
The acid that results when a base accepts a proton is called the **conjugate acid**.

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