Calculate the number of moles and the mass of Ar gas present in a 3.00 L steel container if the pressure is 5.75 atm, and the temperature is 22.0°C. A)1.00 mol, 40.0 g B)0.712 mol, 28.4 g C)9.56 mol, 382 g D)6.20 x 10⁴ mol, 1.55 x 10³ g E)4.59 x 10³ mol, 1.84 x 10⁵ g

Question

Quizplus · Accepted Answer

First, we need to convert the temperature to Kelvin:
T = 22.0°C + 273.15 = 295.15 K

Next, we can use the ideal gas law to solve for the number of moles of gas present:
PV = nRT
n = (PV)/(RT) = (5.75 atm)(3.00 L)/(0.08206 L·atm/mol·K)(295.15 K) = 0.712 mol

Finally, we can use the molar mass of Ar (39.95 g/mol) to calculate the mass of gas present:
m = nM = (0.712 mol)(39.95 g/mol) = 28.4 g

Therefore, the best answer is B.

Calculate the Number of Moles and the Mass of Ar