Osmotic Pressure (Π)Chemistry
van 't Hoff Osmotic Pressure (Π) & Reverse Osmosis Calculator
Calculate colligative osmotic pressure (Π in atm and kPa), biological cell tonicity, and reverse osmosis threshold pressures using the van 't Hoff relation.
Calculated Result
Osmotic Pressure (Π in atm)
12.23bar
Calculator Inputs
mol/L
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Osmotic Pressure (Π in atm)
12.23bar
Osmotic Pressure
1,239.48 bar
Osmotic Pressure
12.39 bar
Osmotic Pressure Verified: Reverse osmosis desalination requires applied hydraulic pressure strictly exceeding this threshold.
Osmotic Pressure Magnitude Profile
Pressure in atm
12.23 atm(100%)
Standard biochemistry and water treatment engineering tool for osmotic equilibria and membrane separation.
Calculation Methodology
van 't Hoff Osmotic Law: Π = i * M * R * T. Where i is the van 't Hoff factor, M is molarity (mol/L), R is the gas constant (0.08206 L atm / (mol K)), and T is temperature in Kelvin (K = °C + 273.15).
Frequently Asked Questions
Because osmotic pressure produces large, easily measurable physical pressure signals (several cm of water or mmHg) even at minute micromolar concentrations, unlike imperceptible freezing point drops.
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