Find out the osmotic pressure of 0.1 M monobasic acid if pH = 2.0 at `25^(@)C`.

Options

A. 2.69 atm
B. 26.9 atm
C. 0.269 atm
D. None of these

Answer

a

Explanation

`{:(HA,hArr,H^(+),+,A^(-)),(C,,0,,0),(C(1-alpha),,Calpha,,Calpha):}`
`[H^(+)] = Calpha = 10^(-2)`
`pH = 2`
`Calpha = 10^(-2) rArr alpha = (10^(-2))/(0.1) = 0.1`
Total number of moles after dissociation
`= C - Calpha + Calpha + Calpha = C(1 + alpha)`
van't Hoff factor `=(C(1 + alpha))/(C) = 1 + alpha = 1 + 0.1 = 1.1`
`pi = iCRT = 1.1xx0.1xx0.0821xx298 = 2.69 atm`