Osmotic Pressure Calculator
This tool calculates the osmotic pressure of a solution using the formula:
π = n × Φ × c × R × T
- n: Number of ions produced by dissociation (van’t Hoff factor).
- Φ: Osmotic coefficient (dimensionless).
- c: Molar concentration of the solution (mol/L).
- R: Universal gas constant (8.314 J/(K·mol)).
- T: Temperature (Kelvin).
What is Osmotic Pressure?
Osmotic pressure is the minimum pressure required to stop the flow of a solvent through a semi-permeable membrane during osmosis. It occurs when two solutions of different concentrations are separated by such a membrane, allowing only the solvent molecules to pass through while blocking solute particles.
The formula to calculate osmotic pressure is:
π = n × Φ × c × R × T
Where:
- π: Osmotic pressure in Pascals (Pa).
- n: Number of ions produced by solute dissociation.
- Φ: Osmotic coefficient, dependent on the solute type.
- c: Molar concentration of the solution in mol/L.
- T: Temperature in Kelvin.
- R: Universal gas constant, equal to 8.314 J/(K·mol).
How to Use the Osmotic Pressure Calculator
- Step 1: Enter the number of ions produced by dissociation (n) in the appropriate field. For example, NaCl dissociates into two ions, so enter “2”.
- Step 2: Input the osmotic coefficient (Φ) for your solute. This value is typically close to “1”. For instance, NaCl has a coefficient of “0.93”.
- Step 3: Specify the molar concentration (c) of your solution in mol/L. If unknown, calculate it using solute mass and solution volume.
- Step 4: Provide the temperature (T) in Kelvin (K). Convert Celsius to Kelvin by adding “273.15”. For example, “25°C” equals “298.15 K”.
- Step 5: Click on the “Calculate Osmotic Pressure” button to compute the result.
- Step 6: Review the displayed result, including a breakdown of inputs and how they were used in calculations.
This tool is ideal for students, researchers, and professionals working in chemistry or related fields who need quick and accurate calculations.