AP Chemistry KMT Questions: Mastering Gas Behavior

📚 Quick Study Guide

• 🌡️ Kinetic Molecular Theory (KMT) describes the behavior of ideal gases.
• 💨 Assumptions of KMT:
  • Particles are in constant, random motion.
  • Collisions are perfectly elastic.
  • Volume of particles is negligible compared to the volume of the container.
  • No intermolecular forces between particles.
• 🧮 Ideal Gas Law: $PV = nRT$, where:
  • $P$ = Pressure
  • $V$ = Volume
  • $n$ = Number of moles
  • $R$ = Ideal gas constant (0.0821 L·atm/mol·K or 8.314 J/mol·K)
  • $T$ = Temperature (in Kelvin)
• ⚖️ Dalton's Law of Partial Pressures: $P_{total} = P_1 + P_2 + ... + P_n$
• 🚀 Graham's Law of Effusion: The rate of effusion is inversely proportional to the square root of the molar mass. $\frac{rate_1}{rate_2} = \sqrt{\frac{M_2}{M_1}}$
• 🌡️ Real Gases: Deviate from ideal behavior at high pressure and low temperature due to intermolecular forces and finite particle volume.

🧪 Practice Quiz

1. Which of the following is NOT an assumption of the Kinetic Molecular Theory?
   1. Particles are in constant, random motion.
   2. Collisions are perfectly inelastic.
   3. Volume of particles is negligible.
   4. No intermolecular forces.
2. According to the Ideal Gas Law, if the number of moles and the temperature are kept constant, and the volume increases, what happens to the pressure?
   1. Increases
   2. Decreases
   3. Remains constant
   4. Fluctuates randomly
3. What is the standard temperature and pressure (STP) in Kelvin and atm, respectively?
   1. 0 K and 1 atm
   2. 273 K and 0 atm
   3. 273 K and 1 atm
   4. 298 K and 1 atm
4. A gas mixture contains 2 moles of nitrogen and 3 moles of oxygen. If the total pressure is 5 atm, what is the partial pressure of nitrogen?
   1. 2 atm
   2. 3 atm
   3. 5 atm
   4. 10 atm
5. Which gas would effuse faster: Helium (He) or Oxygen (O2)?
   1. Helium
   2. Oxygen
   3. They effuse at the same rate.
   4. Cannot be determined.
6. Under what conditions do real gases deviate most from ideal behavior?
   1. High temperature and low pressure
   2. Low temperature and high pressure
   3. Standard temperature and pressure
   4. Ideal conditions
7. If you have 4.4 grams of $CO_2$ gas at STP, what volume will it occupy? (Molar mass of $CO_2$ = 44 g/mol, R = 0.0821 L·atm/mol·K)
   1. 2.24 L
   2. 22.4 L
   3. 4.48 L
   4. 0.224 L