Certified Transport Registered Nurse Certification Practice Exam

What effect does pressure have on gas molecules according to Boyle's Law?

1. It has no effect on them

2. It causes them to speed up

3. It changes their volume

4. It increases their density

The correct answer is: It changes their volume

Boyle's Law states that for a given mass of gas at constant temperature, the pressure of the gas is inversely proportional to its volume. This means that as the pressure exerted on a gas increases, the volume that the gas occupies decreases. Conversely, if the pressure decreases, the volume increases. This relationship highlights how pressure directly impacts the volume of gas molecules, causing them to compress closer together when pressure rises and expand when pressure falls. In practical terms, when pressure is applied to a gas, the molecules are forced closer together, resulting in a decrease in volume. This is observed in various applications, such as in syringes, where pushing the plunger increases pressure inside the barrel and causes the volume of air inside to decrease. Understanding this principle is crucial in fields such as medicine and respiratory therapy, where the behavior of gases can significantly affect patient care and treatment outcomes.