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Equilibrium · Question 39

JEE Main 2025 (Online) 29th January Morning ShiftMCQMedium📈 Topic in 19% papers+4−1
1

At temperature T, compound AB2(g) dissociates as AB2(g) AB(g) + 12B2(g) having degree of dissociation x (small compared to unity). The correct expression for x in terms of Kp and p is:

  1. Kp
  2. [3] 2Kp2p
  3. [3] 2Kpp
  4. [4] 2Kpp

Answer

(2) [3] 2Kp2p

Solution

AB2 AB + 12B2

At equilibrium (moles): AB2: 1 - x, AB: x, B2: x2; total = 1 + x2

x 1 1 - x 1, 1 + x2 1

pAB2 p, pAB xp, pB2 xp2

Kp = pAB (pB2)1/2pAB2 = xp ( xp2 )1/2p = x3/2p1/2 2

x3/2 = 2 Kpp1/2

x3 = 2Kp2p

x = [3] 2Kp2p

Answer: (2)

JEE Main 2025 (Online) 29th January Morning Shift

Keep practising — Equilibrium

2

A weak acid HA has degree of dissociation x. Which option gives the correct expression of (pH - pKa)?

  1. ( 1-xx )
  2. 0
  3. (1+2x)
  4. ( x1-x )
JEE Main 2025 (Online) 28th January Morning Shift
3

Ice and water are placed in a closed container at a pressure of 1 atm and temperature 273.15 K. If pressure of the system is increased 2 times, keeping temperature constant, then identify correct observation from following

  1. Liquid phase disappears completely.
  2. The amount of ice decreases.
  3. The solid phase (ice) disappears completely.
  4. Volume of system increases.
JEE Main 2025 (Online) 28th January Morning Shift
4

Arrange the following in increasing order of solubility product : Ca(OH)2, AgBr, PbS, HgS

  1. PbS < HgS < Ca(OH)2 < AgBr
  2. HgS < AgBr < PbS < Ca(OH)2
  3. HgS < PbS < AgBr < Ca(OH)2
  4. Ca(OH)2 < AgBr < HgS < PbS
JEE Main 2025 (Online) 28th January Evening Shift

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