Question

Two gases occupy two containers A and B. The gas in A of volume 0.11 m³ exerts a pressure of 1.38 MPa. The gas in B of volume 0.16 m³ exerts a pressure of 0.69 MPa. Two containers are connected to one another by a tube of negligible volume and the gases are allowed to intermix. The equilibrium pressure in the container if the temperature remains constant will be

(1) 2.81 MPa

(2) 0.485 MPa

(3) 1.84 MPa

(4) 0.97 MPa

Answer 1

(4) 0.97 MPa

Let n₁ and n₂ be number of moles of gas in A and B. For mixture the number of moles, n, is

n = n₁ + n₂

From ideal gas equation n = pV/RT. At constant temperature

P(V₁ + V₂) = P₁V₁ + P₂V₂

where P is equilibrium pressure in both containers.