A laser tube contains krypton gas (Kr) at 0°C and 1 atm pressure. If the volume of the tube is 22.4 L, approximately how many moles of Kr are present in the tube?

• A. 2 moles
• B. 0.5 mole
• C. 1 mole
• D. 0.1 mole

Answer: (C)

Verified step by step guidance

1. Identify the known variables: temperature (T) = 0°C, pressure (P) = 1 atm, and volume (V) = 22.4 L. Convert temperature to Kelvin by adding 273.15, so T = 273.15 K.
2. Recall the Ideal Gas Law equation: \(P \times V = n \times R \times T\), where \(n\) is the number of moles, and \(R\) is the ideal gas constant.
3. Use the value of the ideal gas constant \(R = 0.0821 \frac{L \cdot atm}{mol \cdot K}\), which is appropriate for the units given.
4. Rearrange the Ideal Gas Law to solve for the number of moles \(n\): \(n = \frac{P \times V}{R \times T}\).
5. Substitute the known values into the equation: \(n = \frac{1 \, atm \times 22.4 \, L}{0.0821 \frac{L \cdot atm}{mol \cdot K} \times 273.15 \, K}\), then simplify to find the number of moles.