The formula to calculate the Osmotic Coefficient (φ) is:
\[ \phi = \frac{\Pi_{obs}}{\Pi_{ideal}} \]
Where:
The osmotic coefficient is a dimensionless number that describes the deviation of a solution from ideal behavior in terms of osmotic pressure. It is used in physical chemistry to account for the non-ideal behavior of solutions, particularly in the context of colligative properties. The osmotic coefficient is defined as the ratio of the observed osmotic pressure to the ideal osmotic pressure. A value of 1 indicates ideal behavior, while values different from 1 indicate deviations due to interactions between solute particles or between solute and solvent particles.
Consider an example where:
Using the formula to calculate the Osmotic Coefficient:
\[ \phi = \frac{2.5}{3.0} = 0.83 \]
This means that the osmotic coefficient for this example is approximately 0.83, indicating a deviation from ideal behavior.