How can you determine if a sample contains an acid or base?

Using a pH test with litmus paper or pH indicators is an effective method for determining whether a sample contains an acid or a base. Litmus paper changes color based on the pH of the solution: red for acidic solutions (pH < 7), blue for basic solutions (pH > 7), and remains purple for neutral solutions (pH = 7). pH indicators also provide a range of colors that correspond to specific pH values, allowing for a clear visual representation of acidity or basicity.

This method is straightforward, quick, and requires minimal equipment, making it ideal for preliminary assessments in the laboratory. It provides immediate results, which can be crucial when assessing samples in a variety of chemical contexts.

Other methods, while useful in specific scenarios, may not be as straightforward for determining acidity or basicity directly. For instance, colorimetric analysis based on turbidity measures the concentration of particles in a solution rather than its pH. Titration with a strong acid can identify the presence of a base, but this process is more complex and involves additional steps. Similarly, thermal decomposition analysis is not directly related to acid-base identification and would focus on the thermal stability and breakdown products of a compound rather than its