ACS Chemistry Practice Exam 2025 – The All-in-One Guide to Exam Success!

The relationship for pressure in a gas is accurately represented by the equation where pressure is defined as the force applied per unit area. This concept comes from the definition of pressure itself, which quantifies how much force is exerted over a specific area.

In simpler terms, pressure tells us how concentrated the force is over a surface area; for instance, if you apply the same force over a smaller area, the pressure increases. This fundamental principle is crucial in understanding behaviors of gases and how they respond to changes in temperature, volume, or force applied.

While other options present various relationships involving pressure, they do not align with this core definition. For instance, the equation stating that pressure equals area divided by force is conceptually incorrect, as it would imply that increasing the area while keeping the force constant would decrease pressure, which contradicts the basic principles of physics. The equation suggesting pressure plus volume equals force also misrepresents how these variables interact.