Ideal Gas Law Equation

The Ideal Gas Law is expressed as: PV=nRT

Where:

• P = Pressure of the gas (in atmospheres, atm)

• V = Volume of the gas (in liters, L)

• n = Number of moles of the gas (in moles, mol)

• R = Ideal gas constant, $0.0821 \, \text{L} \cdot \text{atm} \, \text{K}^{-1} \, \text{mol}^{-1}$

• T = Temperature of the gas (in Kelvin, K)

Key Terms

1. Universal Gas Constant, R:

   • The ideal gas constant, R, is used to relate all units in the equation and has a value of $0.0821 \, \text{L} \cdot \text{atm} \, \text{K}^{-1} \, \text{mol}^{-1}$ when pressure is in atmospheres.

2. Temperature in Kelvin:

   • Temperature must always be in Kelvin (K) for gas law calculations. To convert from Celsius to Kelvin, use: T (K) = T(°C) + 273.15

3. Units Matter:

   • The units for P, V, and T must match the units in the ideal gas constant R to ensure accurate calculations.

   • Typically: P in atm, V in L, T in K, and nnn in moles.

4. Applicability of the Ideal Gas Law:

   • The Ideal Gas Law applies well to ideal gases, which follow all gas laws perfectly under typical conditions.

   • Real gases approximate ideal behavior at high temperatures and low pressures, where gas molecules are far apart.