--- title: "Optical activity, racemates and resolution Template | MolDraw" url: https://www.moldraw.com/templates/stereo-optical-activity/ description: "Optical activity, racemates and resolution template: Specific rotation [α] = α/(l·c), enantiomeric excess from rotation, racemic mixtures, and resolution of…" lang: en publisher: Scidart Academy generated: 2026-10-28 --- [MolDraw](https://www.moldraw.com/) › [Templates](https://www.moldraw.com/templates/) › [Stereochemistry](https://www.moldraw.com/templates/stereochemistry/) › Optical activity, racemates and resolution [Stereochemistry](https://www.moldraw.com/templates/stereochemistry/)Premium # Optical activity, racemates and resolution template ![Optical activity, racemates and resolution template: Specific rotation [α] = α/(l·c), enantiomeric excess from rotation, racemic mixtures, and resolution of a racemic acid through diastereomeric salts of (S)-1-phenylethylamine.](https://www.moldraw.com/templates/stereo-optical-activity.webp) [Edit in MolDraw](https://www.moldraw.com/)Download with Pro Premium template. Preview and edit it free in MolDraw; downloading and exporting it is part of [MolDraw Pro](https://www.moldraw.com/pricing). Specific rotation [α] = α/(l·c), enantiomeric excess from rotation, racemic mixtures, and resolution of a racemic acid through diastereomeric salts of (S)-1-phenylethylamine. ## What the template shows - Enantiomers rotate plane-polarised light equally in opposite directions; a racemate does not rotate it - Measuring and separating enantiomers - α observed rotation (degrees), l path length (dm), c concentration (g mL⁻¹); D = sodium D line (589 nm), T in °C. Example: (S)-(+)-butan-2-ol, [α]D +13.5; (R)-(−)-butan-2-ol, −13.5; the racemate, 0. A sample with [α]D +6.75 has 50 % ee: 75 % (S) and 25 % (R). - racemic acid (R)-RCOOH + (S)-RCOOH - (R)-acid·(S)-amine crystallises (less soluble) - (S)-acid·(S)-amine stays in solution - filter, then add HCl → pure (R)-acid - evaporate, add HCl → (S)-acid - Which salt crystallises depends on the pair; the diagram shows one case. - a common resolving agent - (+) or d: rotates the plane clockwise (dextrorotatory); (−) or l: anticlockwise (laevorotatory). The sign cannot be predicted from R/S. - A racemate (±) is a 1 : 1 mixture of enantiomers: optically inactive. Reactions of achiral reagents through planar intermediates (carbocations, enolates) give racemates. - ee (%) = |% major − % minor| = [α]observed / [α]pure × 100 (optical purity, for an ideal sample). - Enantiomers cannot be separated by crystallisation or ordinary chromatography; diastereomers can, which is why resolution goes through diastereomeric salts (or a chiral column). - Wedge = toward you, hash = away from you · every part of this figure is editable Drawn with 9 atoms, 24 shapes – every one editable in MolDraw. ## Sources - [Clayden, Greeves & Warren, Organic Chemistry, 2nd ed., OUP 2012, ch. 14](https://openlibrary.org/isbn/9780199270293) Textbook - [Eliel & Wilen, Stereochemistry of Organic Compounds, Wiley 1994, ch. 7](https://openlibrary.org/isbn/9780471016700) Textbook - [Moss, Basic terminology of stereochemistry (IUPAC Recommendations 1996), Pure Appl. Chem. 1996, 68, 2193](https://doi.org/10.1351/pac199668122193) IUPAC ## How to use this template 1. Press **Edit in MolDraw**. The template opens on the canvas of the free MolDraw editor. 2. Change anything: move structures, edit atoms and labels, recolour highlights or delete what you do not need. 3. Add your own structures, arrows and text next to it, or combine several templates on one page. 4. Export the drawing as PNG, SVG or PDF for slides, worksheets, theses and papers. ## Frequently asked questions ### Is the Optical activity, racemates and resolution template free? You can preview the Optical activity, racemates and resolution template here and open and edit it in MolDraw for free. Downloading or exporting it is part of MolDraw Pro, together with the other premium templates. ### Can I edit the Optical activity, racemates and resolution template? Yes. It opens as an ordinary MolDraw drawing, so every structure, arrow, label and colour can be changed, and you can add your own content around it. ### Is the chemistry checked? Every structure is checked with RDKit and every curly arrow passes MolDraw’s electron-flow audit. The sources used are listed on this page. ### Are the R/S labels in the stereochemistry templates checked? Yes. Every R/S and E/Z descriptor is computed with RDKit from the drawn structure, so the labels match the wedges and dashes. ## More stereochemistry templates [**Assigning R and S**Free · Stereochemistry](https://www.moldraw.com/templates/stereo-rs-assignment/)[**Newman projections: butane**Free · Stereochemistry](https://www.moldraw.com/templates/stereo-newman-butane/)[**Cyclohexane chair and ring flip**Free · Stereochemistry](https://www.moldraw.com/templates/stereo-chair-ring-flip/)[**CIP priority rules**Premium · Stereochemistry](https://www.moldraw.com/templates/stereo-cip-rules/)[**E/Z and cis/trans alkenes**Premium · Stereochemistry](https://www.moldraw.com/templates/stereo-ez-alkenes/)[**Enantiomers and diastereomers**Premium · Stereochemistry](https://www.moldraw.com/templates/stereo-enantiomers-diastereomers/)[**Meso compounds: 2,3-dibromobutane**Premium · Stereochemistry](https://www.moldraw.com/templates/stereo-meso-dibromobutane/)[**Tartaric acid stereoisomers**Premium · Stereochemistry](https://www.moldraw.com/templates/stereo-tartaric-acid/) ## Related pages [**Chirality & R/S Configuration Worksheet**Free printable worksheet](https://www.moldraw.com/educational-materials/chirality-rs-worksheet/)[**Structural Isomers & Stereoisomers Worksheet**Free printable worksheet](https://www.moldraw.com/educational-materials/isomers-worksheet/)[**All Stereochemistry templates**17 templates](https://www.moldraw.com/templates/stereochemistry/)[**All chemistry templates**370 templates in 29 categories](https://www.moldraw.com/templates/) MolDraw Pro Download all 370 templates - Export the 291 premium templates as PNG, SVG or PDF - AI chemistry assistant - Structure scanning from images - Cloud save and teaching slides [See Pro plans](https://www.moldraw.com/pricing) Free templates stay free. Every template can be opened and edited in MolDraw.