A reaction vessel (volume 0.5 dm³) is filled with 3 mol of hydrogen gas at 25 °C. Calculate the pressure, (in Pa) it exerts using the van der Waals equation. For hydrogen, the van der Waals constants are a = 0.025 Pa m⁶ mol^-2 and b = 2.7 × 10^-5 m³ mol^-1.

Question

Quizplus · Accepted Answer

The van der Waals equation is given by:
(P + a(n/V)²)(V - nb) = nRT

where,
P = pressure
V = volume
n = number of moles
R = gas constant = 8.314 J/molK
T = temperature
a = van der Waals constant
b = van der Waals constant

Substituting the given values, we get:
(P + 0.025(3/0.5)²)(0.5 - 2.7 x 10^-5 x 3) = 3 x 8.314 x 298

Simplifying and solving for P, we get:
P = 1.68 x 10^7 Pa

Therefore, the answer is A.

A Reaction Vessel (Volume 0