At 36°C, what is the osmotic pressure of a 0.82% NaCl by weight aqueous solution? Assume the density of the solution is 1.0 g/mL. (R = 0.0821 L · atm/(K · mol)) a. 7.1 atm b. 0.35 atm c. 0.82 atm d. 4.1 × 102 atm e. 3.5 atm

Respuesta :

Answer: e. 3.5 atm

Explanation:

[tex]\pi =CRT[/tex]

[tex]\pi[/tex] = osmotic pressure  = ?

C= concentration in Molarity

R= solution constant  = 0.0821 Latm/Kmol

T= temperature = [tex]36^0C=(36+273)K=309K[/tex]

For the given solution: 0.82 grams of [tex]NaCl[/tex] is dissolved in 100 g of solution.

[tex]{\text {volume of solution}}=\frac{\text {mass of solution}}{\text {Density of solution}}=\frac{100g}{1.0g/ml}=100ml[/tex]

[tex]Molarity=\frac{\text{Mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{volume of solution in ml}}[/tex]

Putting in the values we get:

[tex]C_{NaCl}=\frac{0.82\times 1000}{58.5\times 100}=0.14M[/tex]

[tex]\pi=0.14mol/L\times 0.0821Latm/Kmol\times 309K[/tex]

[tex]\pi=3.5atm[/tex]

The osmotic pressure of a 0.82% NaCl by weight aqueous solution is 3.5 atm