An aqueous solution contains 1.00 g/L of a derivative of the detergent laurel alcohol. The osmotic pressure of this solution is 17.8 torr, at 25°C. What is the molar mass (in g/mol) of this detergent?

mm = 1043.33 g/mol

Explanation:

osmotic pressure (π):

∴ π = 17.8 torr = 0.0234 atm

∴ Cb: solute concentration

∴ T = 25°C = 298 K

∴ R = 0.082 atm.L/K.mol

⇒ Cb = π/RT

⇒ Cb = (0.0234 atm)/((0.082 atm.L/K.mol)(298 K))

⇒ Cb = 9.585 E-4 mol/L

molar mass (mm):

⇒ mm = (1.00 g/L)(L/9.585 E-4 mol)

⇒ mm = 1043.33 g/mol

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e

the answer is d. 74.02