An unknown ideal gas was added to an evacuated 775 mL container at a temperature of 267.2 K. If 0.381 moles were added, what is the final pressure?
A) 15.8 bar
B) 12.4 bar
C) 9.92 bar
D) 10.9 bar
E) 8.92 bar

Question

Quizplus · Accepted Answer

We can use the ideal gas law equation, PV=nRT, to solve for the final pressure. We are given the initial volume (775 mL), temperature (267.2 K), and number of moles added (0.381 moles). We also know R, the gas constant, is 0.0821 L*atm/mol*K.

First, we need to convert the volume to liters: 775 mL = 0.775 L

Next, we can solve for the final pressure:
PV = nRT
P = nRT/V
P = (0.381 mol)(0.0821 L*atm/mol*K)(267.2 K)/(0.775 L)
P = 10.9 atm

Finally, we can convert the pressure from atm to bar (1 atm = 1.01325 bar):
P = 10.9 atm * (1.01325 bar/1 atm)
P = 11.06 bar, which rounds to 10.9 bar.

Therefore, the best choice is D, with a final pressure of 10.9 bar.

An Unknown Ideal Gas Was Added to an Evacuated 775