CBSE Class 12 · 2003 · All India Compartment · SolutionsShort Answer

Calculate the osmotic pressure of a solution obtained by mixing 100 cm

^{3}

of 0.25 M solution of urea and 100 cm

^{3}

of 0.1 M solution of cane sugar at 293 K. (R = 0.082 L atm mol

^{- 1}

^{- 1}

)

Answer: π ≈ 4.2 atm

Solution

Total moles of solute particles (both are non-electrolytes):

n = 0.25 \times 0.1 + 0.1 \times 0.1 = 0.025 + 0.010 = 0.035 mol

Total volume = 200 cm

^{3}

= 0.2 L, so

C = \frac{0.035}{0.2} = 0.175 M

Osmotic pressure:

π = C R T = 0.175 \times 0.082 \times 293

π = 4.20 atm

CBSE Class 12 Board · 2003 · All India Compartment · Subjective