Question

Could 25g of argon gas in a vessel of volume 1.5 dm exert a pressure of 2.0 bar at 30 °C if it behaved as a perfect gas? If not, what pressure would it exert?

a. Yes, 2.0 bar
b. No, calculate the pressure using the ideal gas law
c. No, pressure cannot be determined
d. Yes, 1.5 bar

Answer 1

Using the ideal gas law, 25g of argon gas at 30 °C in a 1.5 dm³ vessel would exert a pressure of approximately 1.03 bar, not 2.0 bar.

Step-by-step explanation:

To determine if 25g of argon gas could exert a pressure of 2.0 bar in a 1.5 dm3 vessel at 30 °C, we'll use the ideal gas law, which is expressed as PV = nRT. To solve for pressure (P), we rearrange the equation to P = nRT/V. First, let's convert grams of argon to moles (n), using its molar mass (approximately 39.95 g/mol). So, n = 25 g / 39.95 g/mol ≈ 0.6259 mol. Next, we convert volume to liters by noting that 1 dm3 = 1 L, so V = 1.5 L. The ideal gas constant (R) is 0.0831 L·bar/mol·K. The temperature must be in Kelvin, so T = 30 °C + 273.15 = 303.15 K.

Now, we'll plug the values into the ideal gas law: P = (0.6259 mol) * (0.0831 L·bar/mol·K) * (303.15 K) / (1.5 L). Calculating this gives P ≈ 1.03 bar. Therefore, the pressure exerted by the argon gas would be approximately 1.03 bar, not 2.0 bar.

The correct answer is: No, calculate the pressure using the ideal gas law and the pressure would be 1.03 bar.