How do acid-base indicators help determine the pH of a solution without the use of a pH meter?
Acid-base indicators are substances that change color depending on the pH of the solution they are in. They work by undergoing a chemical reaction when they come in contact with acidic or basic substances.
For example, litmus paper is a commonly used acid-base indicator that turns red in the presence of an acid and blue in the presence of a base.
By adding a small amount of the indicator to the solution being tested, the color change can be observed and matched to a chart or table of known color changes for that particular indicator. This allows the pH of the solution to be estimated without the need for a pH meter.
However, it should be noted that the accuracy of this method is not as precise as using a pH meter and can only give a rough estimate of the pH value.