Question

. (10 points) (i) calculate the osmotic pressure of 20 g/l glucose water solution against pure water through a semipermeable membrane at 298.15 k temperature. the semipermeable membrane is not permeable to glucose molecules and is permeable to water molecules. glucose molecular weight is 180.156 g/mol. report the result in [bar]. (ii) adding some sodium chloride (nacl) powder into the glucose solution and it fully dissolved. assuming the semipermeable membrane is permeable to na and clions. will this process change the osmotic pressure value in (i)? briefly explain your answer. (iii) calculate the osmotic pressure of 1 mm glucose water solution against pure water. report the result in [pa].

Answer 1

To calculate the osmotic pressure of a glucose solution, use the equation Π=n/VRT. The osmotic pressure of the 20 g/L glucose solution against pure water is 4.32 atm. Adding NaCl to the solution will increase the osmotic pressure. The osmotic pressure of a 1 mm glucose water solution against pure water is 4.84 x 10^-5 atm.

Step-by-step explanation:

To calculate the osmotic pressure of a glucose solution, we can use the equation:

Π = n/VRT

Where Π is the osmotic pressure, n is the number of moles of solute, V is the volume of solution, R is the gas constant, and T is the temperature in Kelvin.

In this case, the solute is glucose with a molecular weight of 180.156 g/mol. We have a solution with a concentration of 20 g/L. First, we need to convert the concentration from g/L to mol/L:

20 g/L x (1 mol/180.156 g) = 0.1107 mol/L

Next, we need to convert the temperature from degrees Celsius to Kelvin:

298.15 K = 25°C + 273.15

Plugging these values into the osmotic pressure equation:

Π = (0.1107 mol/1 L) / (0.0821 L atm/mol K x 298.15 K) = 4.32 atm

The osmotic pressure of the glucose solution against pure water is 4.32 atm.

ii) Adding sodium chloride (NaCl) to the glucose solution will increase the number of solute particles, thus increasing the osmotic pressure. Since the semipermeable membrane is permeable to Na and Cl ions, the osmotic pressure value will be affected.

iii) To calculate the osmotic pressure of a 1 mm glucose water solution, we need to convert the concentration from mm to mol/L:

1 mm x (1 mol/1000 mm) = 0.001 mol/L

Using the same equation as before:

Π = (0.001 mol/1 L) / (0.0821 L atm/mol K x 298.15 K) = 4.84 x 10^-5 atm

The osmotic pressure of the 1 mm glucose water solution against pure water is 4.84 x 10^-5 atm.