Ohio Assessment for Educators (OAE) Integrated Science (024) Practice Exam

What happens to the volume of a gas when pressure increases at constant temperature?

1. It decreases

2. It increases

3. It remains the same

4. It becomes infinite

The correct answer is: It decreases

When the pressure on a gas increases while keeping the temperature constant, the volume of the gas decreases in accordance with Boyle's Law. This law states that for a fixed amount of gas at a constant temperature, the pressure of the gas is inversely proportional to its volume. This means that as pressure goes up, the volume must go down to maintain that constant relationship, assuming no gas is added or removed from the system. This behavior can be visualized with a piston in a cylinder: if the piston is pressed down (increasing pressure), the space (or volume) the gas occupies must decrease. This principle is fundamental in understanding how gases behave under different conditions, making it essential in both scientific study and practical applications.