An 1% solution of `KCI(I),NaCI(II), BaCI_(2)(III)` and urea (IV), have their osmotic pressure at the same temperature in the ascending order (molar masses of `NaCI, KCI, BaCI_(2)` and urea are respectively `58.5, 74.5, 208.4, 60 g mol^(-1)` Assume 100% ionization of the electrolytes at this temperature

Options

A. `I lt III lt II lt IV`
B. `III lt I lt II lt IV`
C. `I lt II lt III lt IV`
D. `III lt IV lt I lt II`

Explanation

For KCI solution (I) `i=2`
`pi = i(n)/(V) RT = ixx (w)/(M) xx (RT)/(V)`
`= 2 xx (1)/(74.5) xx (RT)/(0.1) = (2)/(7.45) RT`
`= 0.27 RT`
For NaCI solution (II), `i=2`
`pi = 2 xx (1)/(58.5) xx (RT)/(0.1) = (2)/(5.85)RT`
For `BaCI_(2)` solution (III), `i=3`
`pi = 3 xx (1)/(208.4) xx (RT)/(0.1) = (RT)/(20.84) RT`
`= 0.14 RT`
For urea solution (IV), `i=1`
`pi = 1 xx (1)/(60) xx (RT)/(0.1) = (1)/(6) RT`
`= 0.16 RT`
`:'` increasing order of osmotic pressure is
`III lt IVlt I lt II`