A macromolecule is added at a concentration of 18 g L−1 to water at a temperature of 10°C. If the resulting osmotic pressure of this solution is found to be equal to 12 mmHg, es…

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asked Jan 19, 2020 128k views

1 Answer

Robert Fines · Answer 1 · 2020-01-25T16:10:35+0000

Answer: 26138g/mol

Step-by-step explanation:

$\pi =CRT$

$\pi$ = osmotic pressure = 12 mmHg =
(1)/(760)* 12=0.016 atm (760 mmHg= 1atm)

C= concentration in Molarity

R= solution constant = 0.0821 Latm/Kmol

T= temperature =
10^0C=(10+273)K=283K

For the given solution: 18 g of macromolecule is dissolved to make 1 L of solution.

$Molarity=\frac{\text{Mass of solute}* 1000}{\text{Molar mass of solute}* \text{volume of solution in ml}}$

C=(18* 1000)/(M* 1000ml)=(18)/(M)

0.016=(18)/(M)* 0.0821* 283}

M=26138g/mol

The molecular weight of the macromolecule in grams per mole is 26138.