Osmotic pressure of 1 mol of ideal solute relative to pure water is: (PGI June 2009)
## **Core Concept**
The osmotic pressure of a solution is a colligative property that depends on the concentration of solute particles in a solution. For an ideal solute, the osmotic pressure (π) can be calculated using the equation π = cRT, where c is the concentration of the solute in moles per liter (molarity), R is the gas constant, and T is the temperature in Kelvin.
## **Why the Correct Answer is Right**
The correct answer, , represents the osmotic pressure of 1 mole of an ideal solute in 1 liter of solution at a given temperature (usually 0°C or 273.15 K) relative to pure water. Using the equation π = cRT and assuming a temperature of 0°C (273.15 K) and R = 0.0821 L atm/(mol K), for 1 mole of solute in 1 liter of solution, π = 1 * 0.0821 * 273.15 = 22.4 atm. However, when considering the van 't Hoff factor and standard conditions for such problems, is often used directly as a representation of osmotic pressure for 1 mole of solute.
## **Why Each Wrong Option is Incorrect**
- **Option A:** This value seems too low for the osmotic pressure of 1 mole of an ideal solute under standard conditions.
- **Option B:** Similarly, this seems too low and does not align with standard expressions for osmotic pressure.
- **Option D:** This option does not match common expressions for the osmotic pressure of an ideal solution.
## **Clinical Pearl / High-Yield Fact**
A key point to remember is that osmotic pressure is crucial in understanding the behavior of solutions, especially in medical contexts like intravenous fluid administration and dialysis. The standard molar osmotic pressure ( ) is approximately 22.4 liters·atm/(mol·K) at 0°C, but for simplicity and clinical application, expressions like are directly used.
## **Correct Answer:** .