Question

The osmotic pressure of an aqueous solution containing 30.0 g of a newly-isolated protein in one litre of solution is 12.7 mm hg at 25 °c. The approximate molecular weight of protein in g/mol is:

Answer 1

The approximate molecular weight of protein in g/mol is 43950.54.

Given data:

Mass of protein = 30 g

Volume of solution = 1 L

Pressure = 12.7 mmHg (12.7/760 = 0.0167 atm)

Temperature = 25°C (25+ 273 = 298 K)

molecular mass = ?

Solution:

d = PM/RT

d = m/v

R = 0.0821 atm.L / mol.k

now we will put the values in formula.

m/v = PM/RT

30 g/ 1 L = 0.0167 atm × M /  0.0821 atm.L / mol.k ×  298 K

30 g/ 1 L × 0.0821 atm.L / mol.k ×  298 K / 0.0167 atm

733.974 g/mol /  0.0167

43950.54 g/mol