Solubility of BaF in a solution of Ba(NO) will be represented by the concentration term — Ionic Equilibrium Chemistry Question

💡 Solution & Explanation

The dissolution of solid $\text{BaF}_2$ is represented by $\text{BaF}_2\text{(s)} \rightleftharpoons \text{Ba}^{2+}\text{(aq)} + 2\text{F}^-\text{(aq)}$. Because $\text{Ba}^{2+}$ is already present in excess from the strong electrolyte $\text{Ba(NO}_3)_2$, the extent to which $\text{BaF}_2$ dissolves is strictly dictated by the formation of fluoride ions. Since 1 mole of dissolved $\text{BaF}_2$ yields 2 moles of $\text{F}^-$, the molar solubility $S = \frac{1}{2}[\text{F}^-] = 0.5[\text{F}^-]$.