Certainly! Let's break down the problem step by step to identify the correct definition of a Brønsted-Lowry base.
First, we need to understand what the Brønsted-Lowry theory explains about acids and bases:
1. Brønsted-Lowry Acid: A substance that donates a proton ([tex]\( H^{+} \)[/tex]).
2. Brønsted-Lowry Base: A substance that accepts a proton ([tex]\( H^{+} \)[/tex]).
Given this theory, we can evaluate each of the provided options:
- Option A: Decreases [tex]\(\left[ H^{+} \right]\)[/tex] when placed in water: This is related to the behavior of a base but does not precisely define the Brønsted-Lowry concept. It is a secondary effect rather than the direct characteristic of a Brønsted-Lowry base.
- Option B: Increases [tex]\(\left[ H^{+} \right]\)[/tex] when placed in water: This describes the behavior of an acid, not a base.
- Option C: Acts as a proton donor in any system: This description fits a Brønsted-Lowry acid, not a base.
- Option D: Acts as a proton acceptor in any system: This aligns directly with the Brønsted-Lowry definition of a base.
Thus, the correct answer is D) Acts as a proton acceptor in any system.
Therefore, the Brønsted-Lowry base is correctly defined by choice D.
