Question

At room temperature and pressure (RTP), a sample of oxygen (O2) occupies a volume of 10.0 L. How many moles of gas molecules are present, to 3 decimal places?

A. 0.268 moles
B. 0.446 moles
C. 0.804 moles
D. 1.336 moles

Answer 1

To find the number of moles of oxygen gas present at room temperature and pressure (RTP) in a 10.0 L sample, we can use the ideal gas law equation. Plugging in the given values, the number of moles is approximately 0.404 moles.

Step-by-step explanation:

To calculate the number of moles of oxygen gas present, we can use the ideal gas law equation: PV = nRT. Rearranging the equation, n = PV/RT. Given that the pressure (P) is 1 atm, the volume (V) is 10.0 L, the gas constant (R) is 0.0821 L·atm/(mol·K) and the temperature (T) is 298 K, we can plug in these values to find the number of moles (n).

n = PV/RT = (1 atm * 10.0 L) / (0.0821 L·atm/(mol·K) * 298 K) ≈ 0.404 moles.

Rounding to three decimal places, the answer is approximately 0.404 moles. Therefore, the correct option is D. 1.336 moles.