Respuesta :
Answer: The molar mass of the solute is 236.0 g/mol
Explanation:
To calculate the concentration of solute, we use the equation for osmotic pressure, which is:
[tex]\pi=iMRT[/tex]
where,
[tex]\pi[/tex] = osmotic pressure of the solution = 1.33 atm
i = Van't hoff factor = 1 (for non-electrolytes)
M = molarity of solute = ?
R = Gas constant = [tex]0.0821\text{ L atm }mol^{-1}K^{-1}[/tex]
T = temperature of the solution = [tex]27^oC=[273+27]K=300K[/tex]
Putting values in above equation, we get:
[tex]1.33atm=1\times M\times 0.0821\text{ L.atm }mol^{-1}K^{-1}\times 300K\\\\M=\frac{1.33}{1\times 0.0821\times 300}=0.0540M[/tex]
To calculate the molecular mass of solute, we use the equation used to calculate the molarity of solution:
[tex]\text{Molarity of the solution}=\frac{\text{Mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Volume of solution (in mL)}}[/tex]
We are given:
Molarity of solution = 0.0540 M
Given mass of solute = 4.78 g
Volume of solution = 375 mL
Putting values in above equation, we get:
[tex]0.0540M=\frac{4.78\times 1000}{\text{Molar mass of solute}\times 375}\\\\\text{Molar mass of solute}=\frac{4.78\times 1000}{0.0540\times 375}=236.0g/mol[/tex]
Hence, the molar mass of the solute is 236.0 g/mol
