Use this chemistry calculator to reproduce a named relationship with explicit quantities and units for study, laboratory planning, or an independent numerical check.

Osmolality (osmol/kg)

Required number input.

Molality (mol/kg)

Required number input.

i factor

Required number input.

Compute osmotic coefficient phi = osmolality/(i*m). The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Osmotic coefficient

The resulting osmotic coefficient returned as a number.

• Osmotic relationships depend on particle count, concentration basis, temperature, dissociation, membrane selectivity, and solution non-ideality. Osmolality and osmolarity are not interchangeable without density information.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check units and significant figures, compare the result with limiting cases, and use measured or source-specific constants where available. Laboratory, safety, and regulatory decisions require validated methods and appropriate uncertainty analysis.

• Fugacity Coefficient Calculator

  Compute fugacity coefficient phi = f/P.

• Activity Coefficient From Gamma Input

  Compute the ionic activity as the activity coefficient times the molar concentration.

• Debye-Huckel Limiting Law

  Compute an ion activity coefficient in water at 25 °C with the Debye-Hückel limiting law, intended for ionic strength up to 0.01 mol/L.