4.3 Reaction Quotient
The reaction quotient, Q, is equivalent to K in its construction (e.g. it is the ratio of products to reactants) and, for this class, will be treated as dimensionless.
\[Q = \dfrac{[C]^c[D]^d}{[A]^a[B]^b}\] However, it is the ratio of these particles when the reaction is not at equilibrium. Q is only equal to K when the reaction is at equilibrium. Q can be expressed with pressures just like K.