Barium hydroxide, $\text{Ba(OH)}_2$, is a strong electrolyte. In a dilute aqueous solution, it completely dissociates into one barium ion ($\text{Ba}^{2+}$) and two hydroxide ions ($2\text{OH}^-$). The dissociation reaction is given by: $\text{Ba(OH)}_2 \rightarrow \text{Ba}^{2+} + 2\text{OH}^-$ The van't Hoff factor ($i$) is defined as the number of particles formed per formula unit of the solute upon complete dissociation. Since one molecule of barium hydroxide yields a total of 3 ions (1 $\text{Ba}^{2+}$ and 2 $\text{OH}^-$), the value of the van't Hoff factor, $i = 3$.