Water Nuggets Practice Exam

A higher hydrogen ion concentration is an indicator of a solution being more acidic because acidity is defined by the presence of hydrogen ions (H⁺) in a solution. The pH scale, which measures how acidic or basic a solution is, is logarithmic; thus, as the concentration of hydrogen ions increases, the pH value decreases. A solution with a high concentration of hydrogen ions will have a pH less than 7, which categorizes it as acidic.

The other options do not directly relate to acidity. Lower temperature may affect reaction rates or solubility but does not directly indicate acidity. Increased viscosity might change the flow properties of a solution but isn't a measure of acidity. Greater hydroactive particles might suggest increased reactivity or solvation effects, but they do not provide a clear measure of hydrogen ion concentration specifically. Therefore, the true indicator of acidity in a solution is the hydrogen ion concentration.