Provide an example of the equilibrium constant of different reactions.

The equilibrium constant (Kc) is a measure of the extent to which a chemical reaction proceeds.

For example, the reaction A + B ⇌ C + D has an equilibrium constant of Kc = [C][D]/[A][B], where [C], [D], [A], and [B] represent the concentrations of the respective species at equilibrium. If Kc is greater than 1, the reaction favours the products, and if Kc is less than 1, the reaction favours the reactants. If Kc is equal to 1, the reaction is at equilibrium, with equal concentrations of reactants and products.

Another example is the reaction 2H2(g) + O2(g) ⇌ 2H2O(g), which has an equilibrium constant of Kc = [H2O]^2/([H2]^2[O2]). This reaction is exothermic, meaning it releases heat, and has a very large equilibrium constant, indicating that it strongly favours the products.

The equilibrium constant can also be affected by changes in temperature, pressure, and concentration. For example, increasing the concentration of a reactant will shift the equilibrium towards the products, while decreasing the concentration of a product will shift the equilibrium towards the reactants.

Understanding the equilibrium constant is important in many areas of biology, including enzyme kinetics and metabolic pathways. By analysing the equilibrium constant of a reaction, scientists can predict the direction and extent of the reaction under different conditions, and design experiments to manipulate the equilibrium to achieve desired outcomes.