Question

1. A solution of 7.50 mg of a small protein in 5.00 mL aqueous solution has an osmotic pressure of 5.05 torr at 23.1 degrees celcius. What is the molar mass of the protein?

2. A 179 mg sample of a nonelectrolyte isolated from throat lozenges was dissolved in enough water to make 10.0 mL of solution at 25 degrees celcius. The osmotic pressure of the resulting solution was 4.81 atm. Calculate the molar mass of the compound.

Answer 1

We use osmotic pressure equation to solve this problem. From it we can get molarity of the protein. Once we get molarity then we can get moles of it. From the mole, , molarity , volume and mass in g we can get molar mass of protein.

Equation ;

p=CRT

Here p= osmotic pressure in atm, C is molarity (mol/L) R is 0.08206 L atm / K mol , T is in K .

Lests plug given values and get the molar mass of protein.

2 )

We use same method to find out molar mass of protein.