Determine the osmotic pressure of a solution prepared by dissolving 25 mg of `K_2SO_4` in 2 litre of water at 25° C, assuming that it is completely dissociated.

Answer

3096 Pa

Explanation

`V = 450 mL = 0 . 450 L, T = 37^(@) C `
`= (37 + 273) K = 310 K`
`R = 0 . 0 821 L atm K^(-1) mol^(-1)`
`w_(B) = 1 . 0 g`
`M_(B) = 1,85, 00 g mol^(-1)`
`pi = (n_(B) xx R xx T)/( V) = (w_(B) xx R xx T)/( M_(B) xx V)`
`= - ((1 . 0) g xx (0 . 0821 L atm K^(-1) mol^(-1)) xx ( 310 K))/( (1 , 85, 000 g mol^(-1)) xx (0 . 450 L))`
`= 3.057 xx 10^(-4) ` atm
`= 3 .057 xx 10^(-4) atm xx (1 . 013 xx 10^(5) Pa)/( 1 atm)`
= 30 . 967 Pa
[1 atm = 1.013 `xx 10^(5) ` Pa]