Question 3

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 in the solution, making option A the correct answer.

A) Hydrogen (H)

This option is correct because buffers specifically work to minimize fluctuations in the concentration of hydrogen ions (H⁺), which directly affect the acidity of a solution. By either donating or accepting hydrogen ions, buffers help maintain the pH level within a narrow range.

B) Sodium (Na)

This option is incorrect as sodium ions do not play a significant role in buffering capacity. Buffers do not primarily function to regulate sodium ion concentration; instead, they focus on managing hydrogen and hydroxide ion concentrations to stabilize pH levels.

C) Hydroxide (OH)

This option is also incorrect since while hydroxide ions (OH⁻) do influence pH, buffers specifically target the regulation of hydrogen ions. The role of hydroxide ions is secondary in the buffering process, which aims primarily at controlling hydrogen ion concentrations.

D) Potassium (K)

This option is incorrect as potassium ions do not have a direct relationship with the buffering action of solutions. The primary focus of buffers is on hydrogen ions and hydroxide ions rather than on maintaining potassium ion concentrations.

Conclusion

The correct answer is A because buffers are designed to resist changes in hydrogen ion concentration, effectively maintaining the pH of a solution. All other options fail to address the primary function of buffers, which is to manage the acidity of a solution by controlling hydrogen ions rather than the ions listed in options B, C, and D.