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Grade 12Physical Chemistry

The water vapour pressure at 293 k is 2338 pa and the vapour pressure of an aqueous solution is 2295.8 pa.determine it`s osmotic pressure at 313 k if the solution density at this temperature is 1010 kg/m3 . The molecular weight of the solution is 60.

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8 Years agoGrade 12
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ApprovedApproved Tutor Answer1 Year ago

To determine the osmotic pressure of the aqueous solution at 313 K, we can use the formula for osmotic pressure, which is given by the equation:

Osmotic Pressure Formula

The osmotic pressure (π) can be calculated using the formula:

π = iCRT

  • i = van 't Hoff factor (which is 1 for non-electrolytes)
  • C = molarity of the solution
  • R = universal gas constant (approximately 8.314 J/(mol·K))
  • T = temperature in Kelvin

Step 1: Calculate the Molarity of the Solution

First, we need to find the molarity (C) of the solution. Molarity is defined as the number of moles of solute per liter of solution. To find this, we can use the density of the solution and its molecular weight.

The density of the solution is given as 1010 kg/m³. To convert this to grams per liter, we multiply by 1000:

Density = 1010 kg/m³ = 1010 g/L

Next, we can find the number of moles of solute in 1 liter of solution. The molecular weight of the solute is given as 60 g/mol. Therefore, the number of moles of solute in 1 liter is:

Number of moles = Mass (g) / Molecular weight (g/mol) = 1010 g / 60 g/mol = 16.83 mol

Step 2: Calculate the Osmotic Pressure

Now that we have the molarity (C = 16.83 mol/L), we can substitute the values into the osmotic pressure formula. The temperature (T) is given as 313 K, and we will use the gas constant (R) as 8.314 J/(mol·K).

Substituting these values into the osmotic pressure formula:

π = (1)(16.83 mol/L)(8.314 J/(mol·K))(313 K)

Calculating this gives:

π = 1 * 16.83 * 8.314 * 313 ≈ 43,500.57 Pa

Final Result

The osmotic pressure of the aqueous solution at 313 K is approximately 43,500.57 Pa. This value indicates the pressure required to stop the flow of solvent into the solution through a semipermeable membrane, which is a key concept in understanding osmotic processes in biological and chemical systems.