Question

One litre of glucose solution have osmotic pressure \(1.5\) atmosphere is mixed with other \(2\) litre glucose solution of osmotic pressure \(2.5\) atmosphere. Then find resultant osmotic pressure of the solution.

• A. \(0.217\) atm
• B. \(2.17\) atm
• C. \(21.0\) atm
• D. \(216\) atm

Hint:

At the same temperature, osmotic pressure is proportional to concentration, so total moles are added and divided by total volume.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept
\(\pi=CRT\), so at constant temperature \(\pi V\propto n\). The moles of glucose add on mixing.

Step 2: Moles in each solution
\(\pi_1V_1=1.5\times1=1.5\) and \(\pi_2V_2=2.5\times2=5.0\) (in atm L, proportional to \(n\)).

Step 3: Resultant pressure
\(\pi=\dfrac{\pi_1V_1+\pi_2V_2}{V_1+V_2}=\dfrac{1.5+5.0}{3}=\dfrac{6.5}{3}\approx2.17\text{ atm}\).

Step 4: Compare the options
This matches option (B).

Final Answer:
The resultant osmotic pressure is about 2.17 atm. \[ \boxed{\text{(B) }2.17\text{ atm}} \]