Class 11 Equilibrium worksheet

Sample questions

Real questions from this chapter, as the app sets them. Tap Answer to see the answer and working.

Section A · multiple choice

1. 1.

   At equilibrium, the rates of the forward and backward reactions are:

   1. forward faster than backward
   2. backward faster than forward
   3. both zero
   4. equal

   Answer

   (d) equal

   equilibrium is dynamic

2. 2.

   For 2SO₂(g) + O₂(g) ⇌ 2SO₃(g), the equilibrium concentrations are [SO₂] = 0.5 M, [O₂] = 0.5 M, [SO₃] = 0.5 M. K_c is:

   1. 2
   2. 0.5
   3. 4
   4. 1

   Answer

   (a) 2

   K_c = [SO₃]² / ([SO₂]²[O₂])

3. 3.

   For CH₄(g) + H₂O(g) ⇌ CO(g) + 3H₂(g), K_p and K_c are related by:

   1. K_p = K_c(RT)⁻²
   2. K_p = K_c(RT)
   3. K_p = K_c
   4. K_p = K_c(RT)²

   Answer

   (d) K_p = K_c(RT)²

   K_p = K_c(RT)^Δn with Δn = 2

Section B · short answer

1. 4.

   State Le Chatelier’s principle.

   Answer

   If a system at equilibrium is disturbed by a change in concentration, pressure or temperature, it shifts in the direction that tends to undo the change.

2. 5.

   0.5 mol of N₂O₄ is heated in a 2 L vessel. At equilibrium 60% of it has dissociated (N₂O₄(g) ⇌ 2NO₂(g)). Find K_c. (2 decimal places where needed.)

   Answer

   K_c = 0.9 ([N₂O₄] = 0.1 M, [NO₂] = 0.3 M)

   initial 0.25 M; use an ICE table with α

Section C · long answer

1. 6.

   Explain the effect of changing concentration, pressure, temperature and adding a catalyst on the equilibrium N₂(g) + 3H₂(g) ⇌ 2NH₃(g), ΔH = −92.4 kJ/mol.

   Answer

   Adding N₂ or H₂, or removing NH₃, shifts it to the right. Raising the pressure shifts it to the right (4 mol of gas become 2). Raising the temperature shifts it to the left (the forward reaction is exothermic) and lowers K. A catalyst (iron) only makes equilibrium come faster. So high pressure, moderate temperature (about 700 K) and a catalyst are used in the Haber process.

Fresh sheets for your child

In the app, every Equilibrium sheet is new: the app remembers the questions your child has already had and leaves them out. Print the sheet as a PDF, or use notebook mode and write the answers in a notebook.

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