How can qc and kc differ from one another despite having the same algebraic expression? view available hint(s) how can qc and kc differ from one another despite having the same algebraic expression? qc can include pure liquids and solids; kc does not. qc represents the amount of change from initial to equilibrium conditions, whereas kc represents the equilibrium conditions. the two expressions have different units, so they can never be equal unless the proper conversion factor is used. qc is calculated from the current concentrations of the species, while kc only uses the equilibrium concentrations.