When the system 2a b ⇌ 2c d is at equilibrium, the first system will consist of essentially only products, the second system will contain essentially only reactants, and the third system will contain appreciable amounts of both products and reactants.
When a system is at equilibrium, it means that the forward and reverse reactions are occurring at equal rates. In this case, the system 2a + b <↔ 2c + d is at equilibrium. To determine if each statement is true or false:
a) Only system 4 has a large equilibrium constant (K > 10³), indicating that it will consist of essentially only products at equilibrium.
b) System 2 has a small equilibrium constant (K < 10⁻³), indicating that the reactants have little tendency to form products. Thus, at equilibrium, the system will contain essentially only reactants.
c) Both systems 1 and 3 have equilibrium constants in the range 10³ ≥ K ≥ 10⁻³, indicating that the equilibrium mixtures will contain appreciable amounts of both products and reactants.