Calculating Pressure with the Ideal Gas Law: Worked Examples

📚 Quick Study Guide

• ⚛️ The Ideal Gas Law is represented by the equation: $PV = nRT$, where:
• 🌡️ $P$ is pressure (in atm, Pa, or other pressure units).
• ⚗️ $V$ is volume (in liters, $L$, or cubic meters, $m^3$).
• 🧪 $n$ is the number of moles of gas.
• 🔥 $R$ is the ideal gas constant (0.0821 L⋅atm/mol⋅K or 8.314 J/mol⋅K).
• 🌡️ $T$ is temperature (in Kelvin, $K$).
• 🔢 Remember to use consistent units for all variables. Convert temperature to Kelvin using: $K = °C + 273.15$.
• 💡 To calculate pressure ($P$), rearrange the Ideal Gas Law: $P = \frac{nRT}{V}$.

Practice Quiz

1. Question 1: What is the pressure exerted by 2 moles of an ideal gas in a 10L container at 300K?
   1. 0.49 atm
   2. 4.93 atm
   3. 49.26 atm
   4. 492.6 atm
2. Question 2: If you have 0.5 moles of a gas in a 5L container at 27°C, what is the pressure in atm?
   1. 2.46 atm
   2. 0.24 atm
   3. 24.63 atm
   4. 246.3 atm
3. Question 3: A gas occupies 22.4L at 273K and 1 atm. How many moles of gas are present?
   1. 0.5 mol
   2. 1 mol
   3. 2 mol
   4. 22.4 mol
4. Question 4: What volume will 3 moles of a gas occupy at 2 atm and 300K?
   1. 3.69 L
   2. 36.9 L
   3. 369 L
   4. 0.369 L
5. Question 5: If the pressure of a gas is 5 atm, the volume is 10L, and there are 2 moles of gas, what is the temperature in Kelvin?
   1. 30.5 K
   2. 305 K
   3. 3.05 K
   4. 3050 K
6. Question 6: You have a container with a volume of 2.5 L containing 0.75 moles of gas at 298 K. Calculate the pressure in atm.
   1. 7.33 atm
   2. 0.73 atm
   3. 73.3 atm
   4. 733 atm
7. Question 7: Determine the number of moles of gas present if the pressure is 3 atm, the volume is 15 L, and the temperature is 320 K.
   1. 1.72 moles
   2. 0.17 moles
   3. 17.2 moles
   4. 172 moles