A solution containing $2.675\; g$ of $CoCl_3. 6 NH_3$ (molar mass =$ 267.5 \;g \;mol^{–1})$ is passed through a cation exchanger. The chloride ions obtained in solution were treated with excess of $AgNO_3$ to give
$4.78\; g$ of $AgCl$ (molar mass $= 143.5\; g \;mol^{–1}$). The formula of the complex is (At. Mass of $Ag = 108 \;u$)
