Question

Intravenous, or IV, solutions used in medicine must exert the same osmotic pressure as blood to prevent a net flow of water into or out of the blood cells. The proper concentration for an intravenous NaCl solution is 0.90 g NaCl per 100. mL of solution (sometimes referred to as 0.90 % m/v). If the van't Hoff factor of NaCl is i = 1.8 , what is the osmotic pressure of blood at body temperature, 37 ∘ C?

Answer 1

To make an intravenous solution with the same osmotic pressure as blood, you need to calculate the concentration of the solute using the van't Hoff factor. Then, use the van't Hoff equation to calculate the osmotic pressure of the solution.

Step-by-step explanation:

The osmotic pressure of a solution is proportional to the concentration of solute particles in it. The osmotic pressure of human blood at 37°C is 7.6 atm. To make an intravenous solution with the same osmotic pressure as blood, you need to calculate the concentration of the solute. For example, for a glucose solution, you can use the van't Hoff factor, which accounts for the particles the solute dissociates into in solution, to determine the required concentration. Once you have the concentration, you can use the van't Hoff equation to calculate the osmotic pressure of the solution.

Answer 2

The osmotic pressure of blood at 37°C is 7.04 atm.

Step-by-step explanation:

To calculate the concentration of solute, we use the equation for osmotic pressure, which is:

`\pi=icRT`

where:

`\pi` = osmotic pressure of the solution

i = Van't hoff factor

c = concentration of solute

R = Gas constant =
`0.0820\text{ L atm }mol^(-1)K^(-1)`

T = temperature of the solution

We have:

Mass of NaCl = 0.90 g

Moles of NaCl =
`(0.90 g)/(58.5 g/mol)=0.01538 mol`

Volume of NaCl solution = V = 100.0 mL = 0.1 L

Concentration of NaCl solution =
`(0.01538)/(0.1 L)=0.1538 mol/L`

i = 1.8 , T = 37°C = 310.15 K

`\pi =1.8* 0.1538 mol/L* 0.0820\text{ L.atm }mol^(-1)K^(-1)* 310.15 K`

`\pi =7.0407 atm\approx 7.04 atm`

The osmotic pressure of blood at 37°C is 7.04 atm.