Question

Albumins are the most abundant proteins in blood. At 25°C, 3.5g of albumin in 100 ml of water produces an osmotic pressure of 0.014 atm. What is the molecular weight of albumin?

Answer 1

Given: Osmotic pressure, π = 0.014 atm

Temperature, T = 25°C = 298 K

Weight of albumin, w = 3.5 g

Volume of solution, V = 100 mL = 0.1 L

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

We know that

`pi =  n/V RT`

= `w/(M * V) RT`

`M = (wRT)/(pi V)`

`M = (3.5 xx 0.0821 xx 298)/(0.014 xx 0.1)`

= `85.6303/0.0014`

= 61164 g/mol

∴ Molecular weight of albumin = 61164 g/mol