Question

The point at which a substance melts or boils is affected by impurities. Which of the following correctly reflects that fact?

A. The impurity has the effect of lowering both the boiling point and melting point

B. The impurity has the effect of lowering the boiling point and raising the melting point

C. The impurity has the effect of raising both the boiling point and the melting point

D. The impurity has the effect of raising the boiling point and lowering the melting point

Answer 1

Impurities have the effect of lowering both the boiling point and melting point of a substance.

Step-by-step explanation:

The correct answer is A. The impurity has the effect of lowering both the boiling point and melting point.

Impurities in a substance disrupt the regular arrangement of molecules, making it more difficult for the substance to transition from one phase to another. This disruption results in a lower melting point and boiling point. For example, adding salt (an impurity) to water lowers its boiling point and melting point.

Therefore, impurities have the effect of lowering both the boiling point and melting point of a substance.