Which of the following statements is true for ideal gases at standard temperature and pressure (STP)?

• A. The pressure at STP is 2.00 atm.
• B. One mole of an ideal gas occupies 22.4 L at STP.
• C. The volume of one mole of an ideal gas at STP is 1.00 L.
• D. The temperature at STP is 0 °C (273.15 K).

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the definition of STP (Standard Temperature and Pressure). STP is commonly defined as a temperature of 0 °C (273.15 K) and a pressure of 1 atm.
2. Step 2: Recall the ideal gas law equation: \(P V = n R T\), where \(P\) is pressure, \(V\) is volume, \(n\) is number of moles, \(R\) is the ideal gas constant, and \(T\) is temperature in Kelvin.
3. Step 3: Use the ideal gas law to find the volume occupied by one mole of an ideal gas at STP. Substitute \(P = 1\) atm, \(n = 1\) mole, \(T = 273.15\) K, and \(R = 0.0821\) L·atm/(mol·K) into the equation and solve for \(V\).
4. Step 4: Recognize that the calculated volume corresponds to approximately 22.4 L, which is the molar volume of an ideal gas at STP.
5. Step 5: Evaluate the given statements based on these facts: the pressure at STP is 1 atm (not 2 atm), the volume of one mole of ideal gas at STP is about 22.4 L (not 1.00 L), and the temperature at STP is 0 °C (273.15 K). Therefore, the true statement is that one mole of an ideal gas occupies 22.4 L at STP.