Question

Determine the osmotic pressure of a solution prepared by dissolving 2.5

Answer 1

Solution

Given that

Mass of K2SO4, w  = 25 mg  = 0.025g  (use 1 g  = 1000 mg )

Volume V  = 2 liter

T = 25 + 273  = 298 K (add 273 to convert in Kelvin)

The  reaction of dissociation of K2SO4

K2So4  → 2K+  +  SO42-

Number if ions produced  = 2+ 1  = 3

So van’t Hoff factor i  = 3

Use the formula of Osmotic pressure

Gas constant, R = 0.0821 L atm K-1mol-1

Molar mass of K2SO4 ,M = 2 × 39 + 1 × 32 + 4 × 16 = 174 g mol-1

Plug the values we get

π= 5.27 × 10-3 atm

Answer

Osmotic pressure = 5.27 × 10 – 3 atm

Answer 2

Solution

Given that

Mass of K2SO4, w  = 25 mg  = 0.025g  (use 1 g  = 1000 mg ) 

Volume V  = 2 liter

T = 25 + 273  = 298 K (add 273 to convert in Kelvin)

The  reaction of dissociation of K2SO4

K2So4  → 2K+  +  SO42-

 Number if ions produced  = 2+ 1  = 3
So van’t Hoff factor i  = 3

Use the formula of Osmotic pressure 



Gas constant, R = 0.0821 L atm K-1mol-1

Molar mass of K2SO4 ,M = 2 × 39 + 1 × 32 + 4 × 16 = 174 g mol-1

Plug the values we get 



π= 5.27 × 10-3 atm 

Answer

Osmotic pressure = 5.27 × 10 – 3 atm