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

Boiling point (K)

Required number input.

Estimate enthalpy of vaporization via Trouton rule dHvap = 85*Tb J/mol. 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]

dH vap (J/mol)

The resulting dh vap returned as a number.

• The result is conditional on the stated model, constants, standard state, temperature, pressure, composition, and unit basis. Real mixtures and measurements can depart from ideal behavior and carry uncertainty not represented by a single calculated value.
• 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.

• Trouton Rule Estimate

  Estimate the enthalpy of vaporization from the boiling point using Trouton's rule with a 85 J/(mol·K) entropy of vaporization.

• Clausius–Clapeyron Vapor Pressure

  Estimate vapor pressure at a second absolute temperature from a reference pressure and molar enthalpy of vaporization using the integrated Clausius–Clapeyron equation. Assumes vapor behaves ideally and enthalpy stays constant over the temperature interval.

• Clausius Vapor Pressure At T

  Compute the vapor pressure at a second temperature from the Clausius-Clapeyron relation using a reference pressure and enthalpy of vaporization.