The Equilibrium quotient Q In case in which
The Equilibrium quotient (Q) In case in which the concentrations can have any arbitrary values (including zero), this expression is called the equilibrium quotient and its value is denoted by Q (or Qc if we wish to emphasize that the terms represent molar concentrations). If the terms correspond to equilibrium concentrations, then the above expression is called the equilibrium constant and its value is denoted by Kc. Kc is thus the special value that Q has when the reaction is at equilibrium. The value of Q in relation to K indicates the direction in which any net reaction must proceed , the ratio of Q/K immediately tells us whether, and in which direction, a net reaction will occur as the system moves toward its equilibrium state:
Net reaction to reach equilibrium •
But, Kc = 6. 0 x l 0 -2 Thus Q >> K Because Q ≠ K, the system is not in equilibrium. The ratio of products to reactants is too high. In order to achieve equilibrium, the reaction will proceed from right to left (consuming NH 3 and producing N 2 and H 2). Example 6. 3 If 1. 00 mole of each of H 2 and F 2 are placed in a l. 00 L flask. Calculate the equilibrium concentrations of all species if Kc = 55. 3. Answer 6. 3: 1 - Write out the balanced chemical equation: H 2(g) + F 2 ↔ 2 HF (g) Write the equilibrium expression
Multiple Equilibrium •
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