Answer:
The molar mass of unknown β‑Galactosidaseis 116,352.97 g/mol.
Explanation:
To calculate the concentration of solute, we use the equation for osmotic pressure, which is:

where,
= osmotic pressure of the solution = 0.602 mbar = 0.000602 bar
0.000602 bar = 0.000594 atm
(1 atm = 1.01325 bar)
i = Van't hoff factor = 1 (for non-electrolytes)
c = concentration of solute = ?
R = Gas constant = 
T = temperature of the solution = ![25^oC=[273.15 +25]=298.15 K](https://tex.z-dn.net/?f=25%5EoC%3D%5B273.15%20%2B25%5D%3D298.15%20K)
Putting values in above equation, we get:

The concentration of solute is 
Volume of the solution = V =0.137 L
Moles of β‑Galactosidase = n



To calculate the molecular mass of solute, we use the equation:

Moles of β‑Galactosidase = 
Given mass of β‑Galactosidase= 0.387 g
Putting values in above equation, we get:

Hence, the molar mass of unknown β‑Galactosidaseis 116,352.97 g/mol.