Question

For the equilibrium I2(s)+H₂O(l)⇌H+(aq)+I−(aq)+HOI(aq)I what is the Keq expression?

a) [H+][I−]/[I2][H₂O][
b) [H₂O]/[H+][I−]
c) [HOI]/[I2][H+][H₂O]
d) [H+][I−][HOI]/[I2][H₂O][

Answer 1

For the given equilibrium reaction, the correct equilibrium constant expression (Keq) is [H+][I−][HOI] / [I2], as water's concentration is not included because it is a pure liquid.

Step-by-step explanation:

The equilibrium expression, also known as the equilibrium constant (Keq), for the reaction I2(s) + H2O(l) ⇌ H+(aq) + I−(aq) + HOI(aq) involves the concentrations of the products raised to the power of their coefficients divided by the concentrations of the reactants raised to the power of their coefficients.

In this case, the equilibrium expression is given by the formula [H+][I−][HOI] / [I2][H2O]. However, in the expression for Keq, the concentration of water, [H2O], is omitted because it is a pure liquid and its concentration remains essentially constant during the reaction. Therefore, the correct Keq expression is [H+][I−][HOI] / [I2], which corresponds to option (d).