for the reaction H2(g) + Br2(g) ↔ 2HBr(g) the equilibrium constant is given as 0.04 then what is the equilibrium constant for the reaction 2HBr(g) ↔ H2(g) + Br2(g)?

According to the "Law of Chemical Equilibrium," the equilibrium constant is the ratio of the product of the concentration of the products to the product of the concentration of the reactants. Each concentration term raises the stoichiometric coefficient in the balanced chemical equation.