What happens to water's pH when it is mixed with an acid?

When water is mixed with an acid, the pH of the solution decreases, meaning it becomes more acidic. The pH scale ranges from 0 to 14, with values below 7 indicating acidity. Acids release hydrogen ions (H+) when dissolved in water, increasing the concentration of these ions in the solution. This increase in hydrogen ions leads to a lower pH value, showing that the solution is now more acidic compared to pure water, which has a neutral pH of 7.

The other outcomes associated with this question, such as becoming more basic, staying the same, or evaporating, do not accurately describe the interaction. Mixing water with an acid inherently alters the pH and does not maintain it, nor does it lead to evaporation in this context.