One of the most important physical properties that helps identify a substance is its boiling point. The boiling point is the temperature at which a substance transitions from the liquid phase to the gas phase. Different substances have characteristic boiling points, which can be used to distinguish them from one another.
For example, water has a boiling point of 100°C (212°F) at standard atmospheric pressure, while alcohol (ethanol) boils at around 78°C (172°F). By measuring the boiling point of an unknown liquid and comparing it to known values, we can often identify the substance accurately.
In addition to boiling point, other physical properties such as melting point, density, solubility, and color can also aid in identifying substances. Each of these properties can provide valuable information about the substance’s chemical nature and composition.