Answer:
A reversible reaction is a chemical reaction that can proceed in both directions, from reactants to products and from products to reactants. A dynamic equilibrium is a state in which the forward and reverse reactions are happening at the same rate, so that the concentrations of the reactants and products remain constant12. The equilibrium constant expression (Keq) is a mathematical formula that relates the concentrations of the reactants and products at equilibrium. The Keq expression depends on the balanced chemical equation of the reaction, and it has the form of products over reactants, with each concentration raised to the power of its coefficient34. For example, for the reaction:
aA + bB ⇌ cC + dD
The Keq expression is:
Keq = [C]^c [D]^d / [A]^a [B]^b
where [A], [B], [C], and [D] are the equilibrium concentrations of each species, and a, b, c, and d are their coefficients in the balanced equation. The Keq expression does not include any solid or liquid species, as their concentrations are assumed to be constant5.
To write the Keq expression for the chemical reaction performed in this lab, you need to know the balanced equation of the reaction and the states of each species. to balance equations and determine states. Once you have this information, you can write the Keq expression by following the general formula above.