A student reported to her instructor that her unknown contained salt, salicylic acid, and sand. In reality the unknown contained only the first two components, but no sand. What might have led the student to believe sand was present in the unknown? How could the substance be tested to determine if it was actually sand?

Explanation:

From the information given:

The unknown contained salt, salicylic acid, and sand.

It is okay for the student to believe that the sand is present in the unknown, but if we carry how a scientific experiment, we will confirm such a hypothesis if it is right or wrong.

For a test containing salt, salicylic acid, and sand.

We know that the salt is soluble in water, but salicylic acid is sparingly soluble i.e., lightly soluble, and sand is insoluble in water.

So, we will add the unknown mixture into the water. The salt will eventually dissolve first, and then the salicylic acid will dissolve lightly.

Afterward, we will heat the mixture to evaporate the salicylic acid to evaporate, leaving us with the salt.

If there is a positive result of her claim that there is some presence of sand in the evaporated salt sample, that might result from impurities.