Question

$'V' _{1}ml$ of an aqueous urea solution having osmotic pressure equal to 2.4 atm is mixed with $'V' _{2}ml$ of another aqueous urea solution having osmotic pressure equal to 4.6 atm at same temperature. What will be value of $\frac{ V _{1}}{ V _{2}}$ if resulting solution after mixing has osmotic pressure equal to 2.95 atm?

• A. 1
• B. 1.5
• C. 2
• D. 3

Answer 1

Answer: (D)

$\pi_{ R }=\frac{2.4 V _{1}+4.6 V _{2}}{ V _{1}+ V _{2}}=2.95$ atm (assume temperature constant)

$\frac{V_{1}}{V_{2}}=3$.