比尔-朗伯定律计算器
使用比尔-朗伯定律计算溶液的吸光度和浓度。
反应商 (Q)
0.1333
Reaction Quotient (Q) vs Concentration of C [C]
公式
Reaction Quotient (Q)
The reaction quotient has the same mathematical form as the equilibrium constant but is evaluated at non-equilibrium concentrations.
Formula
Q = [C]^c [D]^d / ([A]^a [B]^b)
Compare Q to the equilibrium constant K:
计算示例
For A + B -> C + D with [A]=0.5, [B]=0.3, [C]=0.1, [D]=0.2 M.
- 01Q = [C][D] / ([A][B])
- 02Q = (0.1 × 0.2) / (0.5 × 0.3)
- 03Q = 0.02 / 0.15 = 0.1333
常见问题
What is the difference between Q and K?
K is the equilibrium constant, evaluated only at equilibrium. Q uses the same formula but can be calculated at any point during the reaction. Q tells you which direction the reaction must shift to reach equilibrium.
What about pure solids and liquids?
Pure solids and pure liquids have an activity of 1 and are omitted from the Q expression. Only aqueous species and gases are included.
How does Q relate to Gibbs free energy?
delta_G = delta_G° + RT*ln(Q). At equilibrium, delta_G = 0 and Q = K, giving delta_G° = -RT*ln(K). The sign of delta_G tells the reaction direction.
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