A150.0 ml sample of an aqueous solution at 25°c contains 15.2 mg of an unknown nonelectrolyte compound. if the solution has an osmotic pressure of 8.44 torr, what is the molar mass of the unknown compound? 294 g/mol223 g/mol195 g/mol448 g/mol341 g/mo

The molar mass of the unknown compound is 223.2 g/mol

Explanation:

To calculate the concentration of solute, we use the equation for osmotic pressure, which is:

where,

= osmotic pressure of the solution = 8.44 torr

i = Van't hoff factor = 1 (for non-electrolytes)

M = molarity of solute = ?

R = Gas constant =

T = temperature of the solution =

Putting values in above equation, we get:

To calculate the molecular mass of solute, we use the equation used to calculate the molarity of solution:

We are given:

Molarity of solution =

Given mass of unknown compound = 15.2 mg = 0.0152 g   (Conversion factor:  1 g = 1000 mg)

Volume of solution = 150.0 mL

Putting values in above equation, we get:

Hence, the molar mass of the unknown compound is 223.2 g/mol