What is the effect of acids on pH levels in a solution?

• A. They raise pH levels
• B. They stabilize pH levels
• C. They decrease pH levels
• D. They have no effect on pH levels

Answer: (C)

Acids are substances that release hydrogen ions (H⁺) when dissolved in water. The pH scale measures the concentration of hydrogen ions in a solution, with lower pH values corresponding to higher concentrations of hydrogen ions. This means that when an acid is added to a solution, the increase in hydrogen ion concentration results in a lower pH level.

Therefore, the correct choice indicates that acids decrease pH levels, reflecting their characteristic of elevating the acidity of a solution. This effect is crucial in various physiological processes, as pH levels can significantly influence enzyme activity, metabolic reactions, and overall cellular function. Understanding this concept is fundamental in fields like physiology, biochemistry, and various medical applications, where maintaining appropriate pH levels is essential for health.