When any solution passes through a cation exchange resin that is in acidic form, $$\text{H}^+$$ ion of the resin is replaced by cations of the solution. A solution containing 0.319 g of an isomer with molecular formula $$\text{CrCl}_3 \cdot 6\text{H}_2\text{O}$$ is passed through a cation exchange resin in acidic form. The eluted solution requires $$19 \text{ cm}^3$$ of 0.125 N NaOH. The isomer is