Tools · Calculation

Fractional Distillation Predictor

Predict which fractions you'd actually collect on your column. Antoine boiling points at the column pressure, Fenske analysis on adjacent pairs, azeotrope warnings from the database.

Try a common mixture

EtOH / water 70:30 MeOH / EtOAc 50:50 Hexane / MeOH 50:50 THF / water 95:5 MeCN / water 84:16 Acetone / MeOH 50:50

Load from a stored product — search by CAS, molecule, manufacturer or product name

Column setup

Pressure (mmHg) Target purity (0–1)

Column length 20 cm

5 cm50100150200 cm

Packing

Components

CAS or name	Percent

Vapor pressure: NIST WebBook Antoine constants. Plate count from column length / packing HETP (Perry's 8e §14). Fenske N_min = 2·log[s/(1−s)] / log(α) at total reflux gives the lower bound on plates; reverse-mode planning factor (1.5×) follows the Gilliland correlation. Azeotrope data from CRC Handbook + Dortmund Data Bank.

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