Final Answer:
The concentration of \( \text{H}_2\text{S} \) in the aqueous solution is 0.268 M.
Step-by-step explanation:
The concentration of a compound in a solution refers to the amount of that compound dissolved in a given volume of the solution. Here, the given solution is 0.268 M hydrosulfuric acid (\( \text{H}_2\text{S} \)). This means that in one liter of the solution, there are 0.268 moles of \( \text{H}_2\text{S} \) dissolved.
Hydrosulfuric acid dissociates into its ions in solution: \( \text{H}_2\text{S} \) ⇌ \( \text{H}^+ + \text{HS}^- \). In this equilibrium, some of the \( \text{H}_2\text{S} \) molecules dissociate into \( \text{H}^+ \) ions and \( \text{HS}^- \) ions. However, since the given concentration is stated as 0.268 M for \( \text{H}_2\text{S} \), it means that this concentration considers the total moles of both dissociated and undissociated \( \text{H}_2\text{S} \) in the solution.
Therefore, the concentration of \( \text{H}_2\text{S} \) in the aqueous solution is 0.268 M, representing the total molar amount of \( \text{H}_2\text{S} \) present in the solution per liter. This concentration value encompasses both the undissociated molecules and the ions in equilibrium, giving a comprehensive measure of the substance within the solution.