Dynamic Equilibrium and Equilibrium Constants

Equilibrium Constants

The units of equilibrium constants

Changing the reaction

Example Question:

For the reaction

2H2(g) + S2(g) 2H2S(g)

The Kc was found to be 9.4 x 105 mol-1 dm3 at 1020 K. Equilibrium concentrations were measured as:

[H2(g)] = 0.234 mol dm-3
[H2S(g)] = 0.442 mol dm-3

What is the equilibrium concentration of S2(g) in the above mixture?
  1. First of all, write out the rate equation:
  2. Substitute in the known values:
  3. Rearrange and solve algebraically:

    Useful books for revision

    Revise A2 Chemistry for Salters (OCR A Level Chemistry B)
    Salters (OCR) Revise A2 Chemistry