Gas Sample Calculation: Reflecting on the Ideal Gas Law

How can we determine the number of moles of gas present in a given sample?

Given a gas sample that occupies a volume of 16.4 L at 27°C and 0.300 atm, how many moles of gas are present?

Calculating the Number of Moles of Gas Present

Using the ideal gas law equation PV = nRT, where P is pressure, V is volume, n is the number of moles, R is the ideal gas constant, and T is temperature in Kelvin, we can determine the number of moles of gas present in the sample.

To determine the number of moles of gas present, we can use the ideal gas law equation: PV = nRT, where P is pressure, V is volume, n is the number of moles, R is the ideal gas constant, and T is temperature in Kelvin.

Given:

Pressure (P) = 0.300 atm

Volume (V) = 16.4 L

Temperature (T) = 27°C = 27 + 273.15 = 300.15 K (converted to Kelvin)

We can rearrange the ideal gas law equation to solve for moles (n):

n = PV / RT

Using the values provided and the ideal gas constant R (0.08206 L atm / K mol), we can calculate the number of moles:

n = (0.300 atm * 16.4 L) / (0.08206 L atm / K mol * 300.15 K) ≈ 0.448 moles

The closest option is B) 0.450 moles, which is the correct answer.

In this calculation, it's important to use consistent units (atm for pressure, L for volume, K for temperature) and ensure that the temperature is in Kelvin to match the units of the ideal gas constant.