The van't Hoff factor (i) for a dilute aqueous solution of the strong electrolyte barium hydroxide is :

Ba(OH)₂ is a strong electrolyte, so it completely dissociates in water. The dissociation equation is:

Ba(OH)₂(aq) → Ba²⁺(aq) + 2OH⁻(aq)

From the equation, we can see that one formula unit of Ba(OH)₂ produces three ions (one Ba²⁺ ion and two OH⁻ ions) in solution. Therefore, the van't Hoff factor (i), which represents the number of particles produced per formula unit, is 3.