Consider a mixture ' X ' which is made by dissolving 0.4 mol of $\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_5 \mathrm{SO}_4\right] \mathrm{Br}$ and 0.4 mol of $\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_5 \mathrm{Br}\right] \mathrm{SO}_4$ in water to make 4 L of solution. When 2 L of mixture ' X ' is allowed to react with excess of $\mathrm{AgNO}_3$, it forms precipitate ' $Y$ '. The rest 2 L of mixture ' $X$ ' reacts with excess $\mathrm{BaCl}_2$ to form precipitate ' Z '. Which of the following statements is CORRECT?