NH4HS(s) <-> NH3(g) + H2S(g)

An equilibrium mixture of this reaction at a certain temperature was found to have (NH3)=.268 and (H2S)=.360
What is the value of the equilibrium constant at this temperature?

I posted these two questions to Sara about 30 min ago.

1. Units?
2. Why aren't the values the same?

To find the equilibrium constant (K) at a given temperature, you need to use the concentrations of the reactants and products in the equilibrium mixture. In this case, you have the concentrations of NH3 (0.268 M) and H2S (0.360 M).

The balanced equation for the reaction is:
NH4HS(s) ↔ NH3(g) + H2S(g)

The equilibrium expression for this reaction is:
K = ([NH3] * [H2S]) / [NH4HS]

Substituting the given concentrations, we have:
K = (0.268 * 0.360) / [NH4HS]

The concentration of NH4HS is not given in the problem. However, since it is a solid, its concentration is treated as a constant and does not appear in the equilibrium expression.

Therefore, we cannot calculate the exact numerical value of the equilibrium constant without the concentration of NH4HS.

To find the value of the equilibrium constant (K) at a given temperature, you need to use the equilibrium concentrations of the reactants and products.

In this case, you have the concentrations of NH3 (0.268 M) and H2S (0.360 M) in the equilibrium mixture. However, you don't have the concentration of NH4HS, which is a solid and is not included in the equilibrium expression.

The equilibrium constant expression for the given reaction is:

K = [NH3] * [H2S]

In this expression, square brackets ([ ]) represent the concentration of the species. Since the concentration of NH4HS is not included in the expression, we only consider the concentrations of NH3 and H2S.

Therefore, you can substitute the given concentrations into the equilibrium constant expression:

K = (0.268 M) * (0.360 M)
= 0.09648

So, the value of the equilibrium constant (K) at this temperature is approximately 0.09648.