Which laws can be combined to form the ideal gas law?
A Boyles law and Charles’s law
B Gay-Lussac’s law and Avogadro’s law
C Charles’s law, Avogadro’s law, and Boyle’s law
D Dalton’s law, Gay-Lussac’s law, and Avogadro’s law
The correct answer and explanation is:
The correct answer is C: Charles’s law, Avogadro’s law, and Boyle’s law.
The Ideal Gas Law combines these three fundamental gas laws into one equation that describes the behavior of an ideal gas. Let’s break down how each law contributes to this:
- Boyle’s Law states that at constant temperature, the pressure of a gas is inversely proportional to its volume. Mathematically, this is expressed as P ∝ 1/V, where P is pressure and V is volume. This means that if the volume of a gas decreases, the pressure increases, assuming temperature and the amount of gas are constant.
- Charles’s Law deals with the relationship between the volume and temperature of a gas when pressure and the number of gas molecules are constant. It states that the volume of a gas is directly proportional to its absolute temperature, represented as V ∝ T, where V is volume and T is temperature. In other words, as the temperature of a gas increases, so does its volume, provided pressure and the amount of gas remain constant.
- Avogadro’s Law states that at a constant temperature and pressure, the volume of a gas is directly proportional to the number of gas molecules (moles), expressed as V ∝ n, where V is volume and n is the number of moles of gas. Therefore, if you add more gas to a system (keeping temperature and pressure constant), the volume will increase proportionally.
When combined, these laws form the Ideal Gas Law:
PV = nRT, where P is pressure, V is volume, n is the number of moles of gas, R is the gas constant, and T is temperature.
This equation essentially brings together the relationships described by Boyle’s, Charles’s, and Avogadro’s laws. It allows scientists to predict the behavior of an ideal gas under different conditions, assuming the gas behaves ideally and the intermolecular forces are negligible.