AAMC FL Practice Exam

What does the equation P1V1=P2V2 represent?

1. Relationship between pressure and volume before and after a state change

2. Rate of chemical reaction

3. Energy conservation in closed systems

4. Mass-energy equivalence principle

The correct answer is: Relationship between pressure and volume before and after a state change

The equation P1V1 = P2V2 represents the relationship between pressure and volume of a gas in a closed system undergoing a change of state, often referred to as Boyle's Law. This law states that for a fixed amount of an ideal gas at constant temperature, the product of the pressure and volume before a change (P1V1) is equal to the product of the pressure and volume after the change (P2V2). This principle illustrates that if the volume of a gas decreases, the pressure increases, and vice versa, as long as the temperature remains constant. In dynamic systems involving gas, such as those commonly examined in thermodynamics, this relationship helps to predict how the properties of a gas will change when it is compressed or expanded, making it a foundational concept for understanding gas behaviors. The other choices focus on different scientific principles that do not pertain to the pressure-volume relationship in gases. The rate of chemical reaction refers to kinetics, energy conservation in closed systems is a concept from thermodynamics that deals with total energy within a system, and mass-energy equivalence is related to Einstein's theory, which does not directly describe the behavior of gases under changing conditions. Each of these principles is crucial in its respective context