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#chemical equilibrium

36 public questions tagged with this topic.

For N₂O₄(g) 2NO₂(g) , Kp = 0.16 at 298 K. If the initial pressure of N₂O₄ is 2 atm in a closed vessel, what is the total

Let PNO₂ = 2x , PN₂O₄ = 2 - x , total pressure = 2 - x + 2x = 2 + x . Kp = ((PNO₂)²/PN₂O₄) = ((2x)²/2 - x) = 0.16 , (4x²/2 - x) = 0.16 , 4x² = 0.32 - 0.16x , 4x² + 0.16x - 0.32 = 0 , x² + 0.04x - 0.08 = 0 , x = (-0.04 pm sqrt0.0016 + 0.32/2) , x ≈ 0.27 . Total pressure = 2 + 0.27 = 2.27 atm .

Ref: NCERT Class 11 Chemistry > Chapter 6: Equilibrium > Topic: Relationship Between Kp Kc and Factors Affecting Equilibrium - Le Chatelier

For the reaction 3A(g) + B(g) 2C(g) , Kc = 8 at 500 K. If 1.5 moles of A and 0.5 moles of B are placed in a 1 L vessel,

Initial: [A] = 1.5 M , [B] = 0.5 M , [C] = 0 . Let 2x be moles of C formed, so A decreases by 3x , B by x . At equilibrium: [A] = 1.5 - 3x , [B] = 0.5 - x , [C] = 2x . Kc = ([C]²/[A]³[B]) = ((2x)²/(1.5 - 3x)³ (0.5 - x)) = 8 , (4x²/(1.5 - 3x)³ (0.5 - x)) = 8 . Solving iteratively, x ≈ 0.25 , (0.5)² / [(0.75)³ × 0.25] = 0.25 / 0.1055 ≈ 2.37 (adjust), x ≈ 0.4 , [C] = 2 × 0.4 = 0.8 M .

Ref: NCERT Class 11 Chemistry > Chapter 6: Equilibrium > Topic: Physical Equilibrium - Solid-Liquid Gas-Liquid and Henry's Law

For 2X(g) Y(g) + Z(g) , Kc = 0.01 at 400 K. If 1 mol X is in a 1 L vessel, what is the degree of dissociation at equilib

Initial: [X] = 1 M . Let α be the degree of dissociation, [X] = 1 - α , [Y] = [Z] = (α/2) . Kc = ([Y][Z]/[X]²) = (((α/2))²/(1 - α)²) = 0.01 , (α²/4(1 - α)²) = 0.01 , (α/1 - α) = 0.2 , α = 0.2 - 0.2α , 1.2α = 0.2 , α = 0.167 .

Ref: NCERT Class 11 Chemistry > Chapter 6: Equilibrium > Topic: Physical Equilibrium - Solid-Liquid Gas-Liquid and Henry's Law

For A(g) + 2B(g) 2C(g) , Kp = 0.25 at 400 K. If the total pressure at equilibrium is 4 atm and PA = 1 atm , what is PC ?

Total pressure = PA + PB + PC = 4 , PB + PC = 3 . Kp = ((PC)²/PA (PB)²) = ((PC)²/1 · (3 - PC)²) = 0.25 , PC = 0.5 (3 - PC) , PC = 1.5 - 0.5 PC , 1.5 PC = 1.5 , PC = 1 atm .

Ref: NCERT Class 11 Chemistry > Chapter 6: Equilibrium > Topic: Ionic Equilibrium - Acids Bases and pH and Ionization of Weak Acids Bases

For 2A(g) + B(g) 2C(g) , Kp = 4 at 500 K. If initial pressures are PA = 2 atm , PB = 1 atm , what is PC at equilibrium?

Let PC = 2x , PA = 2 - 2x , PB = 1 - x . Kp = ((PC)²/PA² PB) = ((2x)²/(2 - 2x)² (1 - x)) = 4 , (4x²/(4 - 4x + 4x²)(1 - x)) = 4 , x ≈ 0.8 , PC = 1.6 atm .

Ref: NCERT Class 11 Chemistry > Chapter 6: Equilibrium > Topic: Ionic Equilibrium - Acids Bases and pH and Ionization of Weak Acids Bases

What is the effect of adding an inert gas at constant volume to the equilibrium 2A(g) B(g) + C(g) ?

Adding an inert gas at constant volume does not change the partial pressures or concentrations of the reactants and products, so the equilibrium position remains unaffected.

Ref: NCERT Class 11 Chemistry > Chapter 6: Equilibrium > Topic: Homogeneous and Heterogeneous Equilibria and Applications of Equilibrium Constant

In 2A(g) + B(g) 2C(g) , if Kc = 4 and the equilibrium mixture contains 0.2 mol A , 0.1 mol B , and 0.4 mol C in a 1 L ve

Initial equilibrium: [A] = 0.2 M , [B] = 0.1 M , [C] = 0.4 M , Kc = ((0.4)²/(0.2)²(0.1)) = 4 . After adding 0.1 mol A , [A] = 0.3 M , reaction shifts right to restore equilibrium.

Ref: NCERT Class 11 Chemistry > Chapter 6: Equilibrium > Topic: Homogeneous and Heterogeneous Equilibria and Applications of Equilibrium Constant

For 2NO(g) + O₂(g) 2NO₂(g) , Kc = 100 at 300 K. If 0.2 mol NO and 0.1 mol O₂ are in a 1 L vessel, what is [NO₂] at equil

Initial: [NO] = 0.2 M , [O₂] = 0.1 M , [NO₂] = 0 . Let 2x = [NO₂] , [NO] = 0.2 - 2x , [O₂] = 0.1 - x . Kc = ([NO₂]²/[NO]²[O₂]) = ((2x)²/(0.2 - 2x)²(0.1 - x)) = 100 , (4x²/(0.2 - 2x)²(0.1 - x)) = 100 . Solving, x ≈ 0.09 , [NO₂] = 2 × 0.09 = 0.18 M .

Ref: NCERT Class 11 Chemistry > Chapter 6: Equilibrium > Topic: Homogeneous and Heterogeneous Equilibria and Applications of Equilibrium Constant