Answer to Question #301527 in General Chemistry for dude

Question

An organic compound is known to be nonvolatile and non electrolyte. A 0.35g sample is dissolved in water and diluted to 150mL. The osmotic pressure is measured as 0.04 atm at 250C. The approximate mass number for this compound is 1400g/mol. From the data provided in this problem and knowing that the density Of the solution is 1.00g/mL

a. Calculate the freezing point of the solutions.

b. Determine if the freezing point change would be a good way to determine the molecular mass of the compound.

c. Would the boiling point change be a better determining factor than the freezing point change?

Answer 1

( a ) Delta T_f = i . K_f . m

T_f = - 1 × k_f × m

T_f = - 1 × 1.86 × ( 0.35 / 1400 ) mol . / 0.150 kg

T_f = - 0.00166 degree celcius.

( b ) yes .

( c ) yes .