PYQSide ExamsMy practice

Equilibrium · Question 1

JEE Main 2026 (Online) 8th April Evening ShiftMCQMedium📈 Topic in 13% papers+4−1
1

Consider the following reactions in which all the reactants and products are present in gaseous state 2xy x2 + y2 K1 = 2.5 105 xy + 12z2 xyz K2 = 5 10-3 The value of K3 for the equilibrium 12x2 + 12y2 + 12z2 xyz is :

  1. 2.5 10-3
  2. 2.5 103
  3. 1.0 10-5
  4. 5 10-3

Answer

(3) 1.0 10-5

Solution

Reverse reaction (1) and multiply it by 12:

12x2 + 12y2 xy; K' = ( 1K1 )1/2 = 1 2.5 105 = 1500 = 2 10-3

Add reaction (2): xy + 12z2 xyz; K2 = 5 10-3

Sum: 12x2 + 12y2 + 12z2 xyz

∴ K3 = K' K2 = 2 10-3 5 10-3 = 1.0 10-5

Answer: (3)

JEE Main 2026 (Online) 8th April Evening Shift

Keep practising — Equilibrium

2

Solid carbon, CaO and CaCO3 are mixed and allowed to attain equilibrium at T K. CaCO3(s) CaO(s) + CO2(g) Kp1 = 0.08 atm C(s) + CO2(g) 2CO(g) Kp2 = 2 atm The partial pressure of CO is 10-1 atm

JEE Main 2026 (Online) 8th April Evening Shift
3

One mole each of He and A(g) are taken in a 10 L closed flask and heated to 400 K to establish the following equilibrium. A(g) B(g) Kc for this reaction at 400 K is 4.0. The partial pressures (in atm) of He and B(g) are respectively (at equilibrium) (Assume He, A(g) and B(g) behave as ideal gases) (Given : R = 0.082 L atm K-1 mol-1)

  1. 3.28, 2.624
  2. 2.624, 3.28
  3. 3.28, 0.656
  4. 0.656, 6.56
JEE Main 2026 (Online) 6th April Morning Shift
4

Given is a concentrated solution of a weak electrolyte AxBy of concentration 'c' and dissociation constant 'K'. The degree of dissociation is given by :

  1. [K cx+y-1xxyy ]x+y
  2. ( Kcx+y-1xxyy ) 1x+y
  3. ( cx+y-1xxyyK )x+y
  4. ( cx+y-1xxyyK ) 1x+y
JEE Main 2026 (Online) 6th April Evening Shift
5

In a closed flask at 600 K, one mole of X2Y4(g) attains equilibrium as given below : X2Y4(g) 2XY2(g) At equilibrium, 75% X2Y4(g) was dissociated and the total pressure is 1 atm. The magnitude of rG (in kJ mol-1) at this temperature is . (Nearest Integer) (Given : R = 8.3 J mol-1 K-1; ln 10 = 2.3, log 2 = 0.3, log 3 = 0.48, log 5 = 0.69, log 7 = 0.84)

JEE Main 2026 (Online) 6th April Evening Shift
6

M3A2 is a sparingly soluble salt of molar mass y g mol-1 and solubility x g L-1. The ratio of the molar concentration of the anion ( A3-) to the solubility product of the salt is

  1. 154 y4x4
  2. y5108x4
  3. 108 x5y5
  4. 1108 y4x4
JEE Main 2026 (Online) 5th April Morning Shift
7

Arrange the following resultant mixtures in increasing order of their pH values Choose the correct answer from the options given below :

  1. B < C < A
  2. C < A < B
  3. C < B < A
  4. A < C < B
JEE Main 2026 (Online) 5th April Morning Shift
8

The values of pressure equilibrium constant recorded at different temperatures for the following equilibrium reaction have been given below A(g) B(g) + C(g) array|c|c| 1T ( K-1) & 10 Kp \ 0.05 & 3.5 \ 0.06 & 2.5 \ 0.07 & 1.5 \ array The magnitude of H R calculated from the above data is . (Nearest integer)

JEE Main 2026 (Online) 5th April Morning Shift
9

The reaction A(g) B(g) + C(g) was initiated with the amount 'a' of A(g). At equilibrium it is found that the amount of A(g) remaining is (a − x) at a total pressure of p. The equilibrium constant Kp of the reaction can be calculated from the expression :

  1. x2a2 + x2 p
  2. x2a2 - x2 p
  3. a + x2x2 p
  4. a2 - x2x2 p
JEE Main 2026 (Online) 5th April Evening Shift
10

At T(K), the equilibrium constant of A2(g) + B2(g) C(g) is 2.7 10-5. What is the equilibrium constant for 13A2(g) + 13B2(g) 13C(g) at the same temperature?

  1. (2.7 10-5)3
  2. 6 10-2
  3. 2.7 10-5
  4. 3 10-2
JEE Main 2026 (Online) 4th April Morning Shift
11

The pH of a solution obtained by mixing 5 mL of 0.1 M NH4OH solution with 250 mL of 0.1 M NH4Cl solution is 10-2. (Nearest integer) Given: pKb(NH4OH) = 4.74 2 = 0.30 3 = 0.48 5 = 0.70

JEE Main 2026 (Online) 4th April Morning Shift

All Equilibrium PYQs →

PDFDownload Equilibrium PYQs as PDF Free, with answer key and a QR code to every solution — print it or study offline⬇
All JEE Main Chemistry chapters