Final answer:
The equilibrium expression for the reaction 2aA + 2bB ⇌ 2cC is K = ([C]2c) / ([A]2a[B]2b), utilizing the stoichiometric coefficients from the balanced equation to determine the exponents of the concentration terms.
Step-by-step explanation:
The equilibrium expression for the reaction 2aA + 2bB ⇌ 2cC is based on the concentrations (or partial pressures for gases) of the reactants and products at equilibrium. According to the law of mass action, the equilibrium constant expression for a general reaction aA + bB ⇌ cC + dD is given by [C]c[D]d / ([A]a[B]b), where the square brackets denote the concentration of a species, and the letters a, b, c, and d represent the stoichiometric coefficients in the balanced equation.
For this particular reaction, assuming it occurs in a solution where concentrations are used, the equilibrium expression would be:
K = ([C]2c) / ([A]2a[B]2b)
The positions of reactants and products in the equilibrium expression are based on the reaction being balanced with the coefficients provided. It is important to raise the concentration terms to the power of their respective coefficients in the balanced equation.