Question

The osmotic pressure of 250mL of an aqueous solution containing 0.150g of the enzyme lysozyme is found to be 0.0013atm at 24.850 Calculate the molar mass of lysozyme.

Answer 1

$\pi$ = iMRT

$\pi$ - osmotic pressure (atm)

i - van't Hoff's factor

M - molar concentration of solution (mol/l)

M = m(solute)/[Mr(solute)xV(solution)]

R - ideal gas constant (0.08206 l atm mol^-1 K^-1)

T - temperature (K)

0.0013 atm = 1 x 0.150 g / [Mr(lysozyme)x0.250 l] x 0.08206 l atm mol^-1 K^-1 x (24.850 + 273.15 K)

Mr(lysozyme) = 11 286.4 g/mol