Question

The osmotic pressure in atmospheres of $10\%$ solution of cane sugar at ${69}^{o}C$ is?

• A. $724$
• B. $824$
• C. $8.21$
• D. $7.21$

Answer 1

Answer: (C)

$8.21$

Osmotic pressure, $\pi =iCRT$

Given that-

$T={69}^{o}C=69+273=342K$

Mol. wt. for sugar = 342 g/mol, vant Haff factor for sugar, i=1

In 10% solution of sugar-

mass of sugar = 10 g

mass of solution = 100 g

Volume of solution = 100 ml ($\because d=1g/ml$)

Concentration of sugar solution, $C=\frac{n}{V\left(inml\right)}\times 1000$

$n=\frac{10g}{342gmo{l}^{-1}}$, $V=100ml$

$\pi =\frac{1\times 10\times 0.082\times 342\times 1000}{342\times 100}$

$\pi =8.21$ atm

Hence, the correct option is C.