Combined Gas Law Examples in Real Life

📚 Quick Study Guide

• 🌡️ The Combined Gas Law relates pressure ($P$), volume ($V$), and temperature ($T$) of a fixed amount of gas: $\frac{P_1V_1}{T_1} = \frac{P_2V_2}{T_2}$.
• 📏 This law is derived from combining Boyle's Law, Charles's Law, and Gay-Lussac's Law.
• ⚠️ Temperature must be in Kelvin (K) for accurate calculations: $K = \text{°C} + 273.15$.
• ⚗️ The law assumes the amount of gas (number of moles) remains constant.
• 💡 Remember to use consistent units for pressure and volume.

🧪 Practice Quiz

1. A gas occupies 10L at standard temperature and pressure (STP). If the pressure is doubled and the temperature is increased to 546.3 K, what is the new volume?
   1. 5L
   2. 10L
   3. 20L
   4. 40L
2. A balloon contains 5L of air at 27°C and 1 atm. If the temperature is increased to 227°C and the pressure is decreased to 0.5 atm, what is the new volume?
   1. 5L
   2. 10L
   3. 15L
   4. 20L
3. A gas in a container has a volume of 6.0 L at a pressure of 2.0 atm and a temperature of 300 K. If the pressure is changed to 4.0 atm and the temperature is changed to 600 K, what is the new volume?
   1. 3.0 L
   2. 6.0 L
   3. 12.0 L
   4. 24.0 L
4. A scuba tank contains oxygen at 20°C and a pressure of 150 atm. If the tank is heated to 30°C, what is the new pressure inside the tank, assuming the volume remains constant?
   1. 140 atm
   2. 155 atm
   3. 160 atm
   4. 165 atm
5. A car tire has a volume of 30 L at a pressure of 2.0 atm and a temperature of 27°C. After a long drive, the temperature increases to 57°C and the volume increases to 31 L. What is the new pressure in the tire?
   1. 1.0 atm
   2. 2.1 atm
   3. 3.0 atm
   4. 4.2 atm
6. A weather balloon is filled with 100 L of helium at 25°C and 1.0 atm pressure at sea level. As the balloon rises, the temperature drops to -5°C and the pressure decreases to 0.5 atm. What is the new volume of the balloon?
   1. 50 L
   2. 100 L
   3. 182 L
   4. 200 L
7. A sample of gas has a volume of 5.0 L at 25°C and 1.5 atm. If the volume is compressed to 2.5 L and the temperature is increased to 50°C, what is the new pressure?
   1. 0.75 atm
   2. 1.5 atm
   3. 3.3 atm
   4. 6.6 atm