1. What is the Osmotic Pressure Formula?

The osmotic pressure formula (Π = iCRT) describes the pressure required to stop osmosis across a semipermeable membrane. It's a colligative property that depends on the number of solute particles in solution.

2. How Does the Calculator Work?

The calculator uses the osmotic pressure equation:

Where:

• \( \Pi \) — Osmotic pressure (atm)
• \( i \) — Van't Hoff factor (dimensionless)
• \( C \) — Molar concentration (mol/L)
• \( R \) — Ideal gas constant (0.0821 L·atm/mol·K)
• \( T \) — Absolute temperature (K)

Explanation: The equation shows that osmotic pressure is directly proportional to the molar concentration of solute particles and the absolute temperature.

3. Importance of Osmotic Pressure

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

4. Using the Calculator

Tips: Enter the Van't Hoff factor (1 for non-electrolytes, higher for electrolytes), molar concentration in mol/L, and temperature in Kelvin. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What is the Van't Hoff factor?
A: It represents the number of particles a compound dissociates into in solution (e.g., 1 for glucose, 2 for NaCl, 3 for CaCl₂).

Q2: Why must temperature be in Kelvin?
A: The equation uses absolute temperature because osmotic pressure is directly proportional to thermodynamic temperature.

Q3: What are typical osmotic pressure values?
A: Physiological solutions (~300 mOsm) have about 7.3 atm at 37°C. Seawater has about 25-30 atm.

Q4: How does this relate to medical solutions?
A: IV solutions are classified as isotonic (~300 mOsm), hypotonic, or hypertonic based on their osmotic pressure relative to blood.

Q5: Can this be used for non-ideal solutions?
A: For highly concentrated solutions, activity coefficients should be used instead of molar concentrations.