Question

37. Calculate the osmotic pressure of a sugar solution in which 3.42 g of sugar has been dissolved in 100 cm^3
of solution at 300 K.
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Answer 1

Given:-

→ Mass of sugar dissolved = 3.42g

→ Volume of solution = 100cm³ = 0.1 L

→ Temperature = 300 K

To find:-

→ Osmotic pressure of the sugar solution.

Solution:-

Molar mass of sugar [C₁₂H₂₂O₁₁] :-

= 12×12 + 1×22 + 16×11

= 144 + 22 + 176

= 342g/mol

Firstly, let's calculate the molar concentration of solute [sugar] in the solution :-

= Moles of solute/Litres of solution

= 3.42/342/[0.1]

= 0.01/0.1

= 0.1 mol L⁻¹

_____________________________

Now, we know that :-

Π = CRT

Where :-

• Π is the osmotic pressure.

• C is molar concentration of solute.

• R is Ideal Gas Constant [0.082].

• T is temperature.

Substituting values, we get :-

=> Π = 0.1 × 0.082 × 300

=> Π = 2.46 atm

Thus, osmotic pressure of the sugar solution is 2.46 atm .