Final answer:
A solution is considered neutral when the hydrogen ion concentration and hydroxide ion concentration are equal. This equality is an essential characteristic of neutral solutions and helps determine the properties and behavior of different types of solutions.
Step-by-step explanation:
A solution is considered neutral when the hydrogen ion concentration ([H3O+]) is equal to the hydroxide ion concentration ([OH-]). This means that the concentrations of both ions are equal, with a value of 1.0 × 10-7 M. In neutral solutions, the product of the two concentrations, [H3O+][OH-], is always equal to 1.0 × 10-14.
This equality of hydrogen ion concentration and hydroxide ion concentration is a key characteristic of neutral solutions and is important in understanding the properties and behavior of different types of solutions.
For example, in pure water, the concentration of hydrogen ions and hydroxide ions are equal, making it neutral. In acidic solutions, the hydrogen ion concentration is greater than the hydroxide ion concentration, while in basic solutions, the hydroxide ion concentration is greater than the hydrogen ion concentration.