Final answer:
A solution with a pH of 5 has 100 times the hydrogen ion concentration compared to a solution with a pH of 7, due to the logarithmic nature of the pH scale.
Step-by-step explanation:
Compared with a pH of 7, a solution of pH 5 has a hydrogen ion concentration that is 100 times greater. The pH scale is logarithmic, meaning that each whole pH unit change corresponds to a tenfold change in hydrogen ion concentration. Therefore, moving from pH 7 to pH 6 increases the hydrogen ion concentration by a factor of 10, and moving again from pH 6 to pH 5 increases it by another factor of 10, thus yielding a total increase by a factor of 100.