What does it signify if Kc is less than 1?

When the equilibrium constant, Kc, is less than 1, it indicates that at equilibrium, the concentration of the reactants is higher than that of the products. This is because Kc is defined as the ratio of the concentration of the products to the concentration of the reactants at equilibrium. A Kc value less than 1 means the numerator (product concentration) is smaller than the denominator (reactant concentration), which signifies that, at equilibrium, the system favors the formation of reactants over products.

This scenario typically occurs in reactions where the forward reaction does not strongly favor the formation of products, meaning that more of the original reactants remain compared to the amount converted into products. Thus, when Kc is less than 1, it reflects a tendency towards a higher concentration of reactants in the system at equilibrium.