1. What is Osmotic Pressure?

Osmotic pressure (Π) is the minimum pressure which needs to be applied to a solution to prevent the inward flow of its pure solvent across a semipermeable membrane. It's a colligative property, meaning it depends on the molar concentration of the solute but not its identity.

2. How Does the Calculator Work?

The calculator uses the osmotic pressure equation:

Where:

• \( \Pi \) — Osmotic pressure (atm)
• \( M \) — Molar concentration (mol/L)
• \( R \) — Ideal gas constant (0.08206 L·atm/(mol·K))
• \( T \) — Absolute temperature (K)

Explanation: The equation shows the direct relationship between osmotic pressure and molarity at a given temperature.

3. Importance of Osmotic Pressure

Details: Osmotic pressure is crucial in biological systems (like cell membrane function), industrial processes (reverse osmosis), and medical applications (IV solutions).

4. Using the Calculator

Tips: Enter molarity in mol/L and temperature in Kelvin. Remember that 0°C = 273.15K. The calculator assumes ideal behavior.

5. Frequently Asked Questions (FAQ)

Q1: What is the van't Hoff factor?
A: For non-ideal solutions, the equation becomes Π = iMRT, where i is the van't Hoff factor accounting for solute dissociation.

Q2: How does temperature affect osmotic pressure?
A: Osmotic pressure increases linearly with absolute temperature according to the equation.

Q3: What are typical osmotic pressure values?
A: Physiological saline (0.9% NaCl) has Π ≈ 7.6 atm at 37°C. Seawater has Π ≈ 30 atm.

Q4: When is this equation not valid?
A: For very concentrated solutions or solutions with strong solute-solvent interactions where non-ideal behavior becomes significant.

Q5: How is this related to reverse osmosis?
A: Reverse osmosis applies pressure greater than Π to force solvent from the solution side to the pure solvent side.