Question

Find the osmotic pressure of 0.01 M solution at 25 °C \((R = 0.0821 \text{L atm mol}^{-1}\text{K}^{-1})\)

• A. \(0.201\) atm
• B. \(0.245\) atm
• C. \(0.082\) atm
• D. \(0.41\) atm

Hint:

Apply pi = CRT with T converted to kelvin.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept
Osmotic pressure of a dilute solution follows the van 't Hoff relation, which looks like the ideal gas equation.

Step 2: Key Formula or Approach
\[ \pi=CRT \]
where \(C\) is molarity, \(R=0.0821\ \text{L atm mol}^{-1}\text{K}^{-1}\) and \(T\) is in kelvin.

Step 3: Convert temperature
\[ T=25+273=298\ \text{K} \]

Step 4: Calculation
\[ \pi=0.01\times0.0821\times298=0.2447\ \text{atm}\approx0.245\ \text{atm} \]

Step 5: Check the options
Option (C) 0.082 comes from forgetting T. Option (D) 0.41 and (A) 0.201 do not follow from any correct use of the formula. The right value is 0.245 atm, option (B).

Final Answer:
The osmotic pressure is about 0.245 atm, option (B). \[ \boxed{0.245\ \text{atm}} \]