The observed osmotic pressure for a `0.10M` solution of `Fe(NH_(4))_(2)(SO_(4))_(2)` at `25^(@)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^(-) mol^(-1))`

Options

A. 5 and 4.42
B. 4 and 4.00
C. 5 and 3.42
D. 3 and 5.42

Answer

A

Explanation

Given `pi_(ob) = 10.8 atm`
`pi_("nor")=CRT = 0.10 xx 0.0821xx 298 = 2.446`
Now experimental value of (i)
`=("Observed osmotic pressure")/("Normal osmotic pressure")=(10.8)/2.446 = 4.42`