Figure 2.

Example system of coupled chemical equilibrium reactions illustrating detailed balance and the mass-balance approach. (a) Reaction set for the formation of AAB trimers from A and B monomers via bimolecular equilibrium reactions. (b) The conditions on equilibrium concentrations. (c) Free energy diagram. (d) Mass-balance equations for the two building blocks A and B. (e) Equilibrium concentrations of the five species in a titration experiment as solved from these two mass-balance equations for ΔG₁^° = −21 kJ·mol^–1, ΔG₂ = −28 kJ·mol^–1, and ΔG₃^° = −30 kJ·mol^–1 at T = 293 K and a total concentration of 0.5 mM.