The observed osmotic pressure for a 0.10 M solution of $\;Fe(NH_{4})_{2}(SO_{4})_{2}\;$ at $\;24^{0}C\;$ is 10.8 atm . The expected and experimental (observed) values of Van't Hoff factor (i) will be respectively : $\;(R=0.082\;L\; atm\; k^{-1} mol^{-1})$