As shown schematically in the figure, two vessels contain water solutions (at temperature T ) of potassium permanganate KMnO 4 of different concentrations n 1 and n 2 n 1 n 2 molecules per unit volume with Δ n = n 1 - n 2 ≪ n 1 . When they are connected by a tube of small length l and cross-sectio

Question

As shown schematically in the figure, two vessels contain water solutions (at temperature T ) of potassium permanganate KMnO 4 of different concentrations n 1 and n 2 n 1 > n 2 molecules per unit volume with Δ n = n 1 - n 2 ≪ n 1 . When they are connected by a tube of small length l and cross-sectional area S , KMnO 4 starts to diffuse from the left to the right vessel through the tube. Consider the collection of molecules to behave as dilute ideal gases and the difference in their partial pressure in the two vessels causing the diffusion. The speed v of the molecules is limited by the viscous force - β v on each molecule, where β is a constant. Neglecting all terms of the order Δ n 2 . Which of the following is/are correct? ( k B is the Boltzmann constant)

Quantrex Academy · Accepted Answer

Correct answer: C. total number of molecules going across the tube per sec is &#916; n l k B T &#946; S

(a) F = Δ P . A = P 1 - P 2 A = n 1 × RTA - n 2 RT . A F = Δ n R T A (b) β v × n 1 × A × ℓ = Δ n k B T A β v n 1 ℓ = Δ n k B T (c) dN dt = S v n 1 = s n 1 × Δ n k B T β n 1 ℓ = S × Δ n k B T S β ℓ (d) Δ n → decreasing then d N d t → decreasing

JEE Advanced Physics Question (2020) — Solution

Question

Options

Answer

Step-by-step solution