A student is given a sample of an unknown liquid to test in a lab investigation. The student thinks that the liquid is water. Which of the following physical properties of the sample is most helpful to determine if the liquid is water?

Question

Responses
A The boiling point of the liquidThe boiling point of the liquid
B The mass of the liquidThe mass of the liquid
C The color of the liquidThe color of the liquid
D The smell and taste of the liquid

Answer 1

The most helpful physical property of the sample to determine if the liquid is water is:

A. The boiling point of the liquid.

Water has a specific boiling point (100°C or 212°F at 1 atmosphere of pressure), which can be used as a definitive criterion to identify if the unknown liquid is indeed water. The other options, such as mass, color, and smell/taste, are not specific enough to definitively identify water, as many liquids can share similar characteristics.