Chemical Equilibrium: Understanding the Equilibrium Constant

What is the equilibrium concentration of H2S?

If the equilibrium constant for this system is 8.5 x 10-3 and the equilibrium concentration of NH3 is 9.2 x 10-2 M, what is the equilibrium concentration of H2S?

Answer:

A. 9.2 x 10-2 M.

According to chemical equilibrium, the equilibrium concentration of H2S is 9.2 x 10⁻² M. Chemical equilibrium is defined as the condition which arises during the course of a reversible chemical reaction with no net change in the amount of reactants and products.

A reversible chemical reaction is one where the products, as soon as they are formed, react together to produce back the reactants. At equilibrium, the two opposing reactions take place at equal rates and there is no net change in the amount of substances involved in the chemical reaction.

Factors that affect chemical equilibrium include changes in concentration, pressure, temperature, and the presence of a catalyst. The equilibrium constant for this system is given by [NH₃][H₂S]. Therefore, by calculating [H₂S] = 8.5 x 10⁻³ / 9.2 x 10⁻², we find that the equilibrium concentration of H2S is 9.2 x 10⁻² M.