The easiest way to determine if a solution is acidic, we need to determine its pH. There are four ways that can be used to determine the pH of a solution. The choice will be determined by the available supplies as well as how precise you need to have the value of the pH.
1. pH sensors can be used to precisely determine the pH of a solution. They are an electronic device and must be calibrated before use so there is some prep work to do in order to use these.
2. An indicator can be used to determine whether a solution is acidic or basic. For a simple acid/base determination, phenophthalein is typically a good choice. If you need a more precise answer, then a combination of indicators can be used.
3. pH paper is a very quick way to determine the approximate pH of a solution. A small drop of the solution is placed on the pH paper and the resulting color is compared to a chart which shows the relationship between the color and the pH value.
4. Litmus paper can also be used to do a quick acid/base test. Neutral litmus paper typically turns blue in base and red in acid using the same dotting technique described for pH paper.