Question 2

A buffer resists changes in the concentration of Hydrogen (H+) ions.

Buffers are solutions that help maintain a stable pH by resisting changes in the concentration of hydrogen ions (H+). This ability is crucial in various biological and chemical processes, making option C the right choice.

A) Sodium (Na+)

Sodium ions (Na+) are not the primary focus of buffer solutions. Buffers specifically target the regulation of hydrogen ion concentration to maintain pH levels, thus making this option incorrect in the context of the question.

B) Hydroxide (OH-)

While hydroxide ions (OH-) are involved in acid-base reactions, they do not define the buffering action. Buffers primarily act to stabilize hydrogen ion concentrations rather than hydroxide ions, rendering this option incorrect.

C) Hydrogen (H+)

Buffers are designed to resist changes in the concentration of hydrogen ions (H+), which directly influences the pH of a solution. This characteristic is essential for maintaining homeostasis in biological systems, confirming that this option is correct.

D) Potassium (K+)

Potassium ions (K+) are not directly related to the buffering action of a solution. The primary concern of buffers is controlling the concentration of hydrogen ions, thus making this option incorrect.

Conclusion

The correct answer, hydrogen ions (H+), is crucial in defining the function of buffers in a solution. All other options do not pertain to the fundamental role of buffers, which is to stabilize pH by resisting changes in hydrogen ion concentration. This distinction emphasizes the importance of H+ in the buffering process.