Question

An electrolyte ab is 100% ionised in10% aqueous solution what is the osmotic pressure of the solution if molecular wtis 200

Answer 1

Therefore the osmotic pressure of the solution is 24.6 atm

Given : An electrolyte AB is 100% ionised in 10% aqueous solution and also molecular weight of AB is 200 g/mol

To find : The osmotic pressure of the solution.

solution : An electrolyte AB is 100% ionised in aqueous solution.

so Van't Hoff factor, i = 1 + α = 1 + 1 = 2 [ for 100% ionisation, α = 1 ]

10% of aqueous solution means 10g of AB electrolyte in 100 ml of aqueous solution.

so, no of moles of AB = given weight/molecular weight

= 10/200 = 1/20 = 0.05

now using formula, π = i(n/V)RT

where π is osmotic pressure, n is no of moles , V is volume of solution, R is universal gas constant and T is temperature.

Temperature is given, T = 300 K [ which you forgot to mention]

π = 2 × {0.05/(100/1000)} × 0.082 × 300 K

= 2 × 0.5 × 0.082 × 300

= 24.6 atm.

Therefore the osmotic pressure of the solution is 24.6 atm