--- title: "Lucas test Template – Chemistry Diagram | MolDraw" url: https://www.moldraw.com/templates/lucas-test/ description: "Lucas test template: ZnCl₂ binds the OH oxygen, the C–O bond breaks to a tertiary carbocation and chloride captures it; the insoluble tert-butyl chloride…" lang: en publisher: Scidart Academy generated: 2026-10-28 --- [MolDraw](https://www.moldraw.com/) › [Templates](https://www.moldraw.com/templates/) › [Name reactions](https://www.moldraw.com/templates/name-reactions/) › Lucas test [Name reactions](https://www.moldraw.com/templates/name-reactions/)Premium # Lucas test template ![Lucas test template: ZnCl₂ binds the OH oxygen, the C–O bond breaks to a tertiary carbocation and chloride captures it; the insoluble tert-butyl chloride makes the solution turbid immediately.](https://www.moldraw.com/templates/lucas-test.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). ZnCl₂ binds the OH oxygen, the C–O bond breaks to a tertiary carbocation and chloride captures it; the insoluble tert-butyl chloride makes the solution turbid immediately. ## Mechanism step by step ZnCl₂ in conc. HCl converts a tertiary alcohol to its chloride at once (SN1) 1. **Lewis acid binds O** – The OH oxygen gives a lone pair to ZnCl₂ 2. **Ionisation (slow)** – C–O breaks: a tertiary carbocation 3. **Chloride adds (fast)** – Cl⁻ captures the carbocation ## Key points - Rate follows carbocation stability: 3° turbid at once, 2° in about 5 minutes, 1° no turbidity at room temperature. - The alcohol dissolves in the reagent; the alkyl chloride does not, hence the cloudiness. - ZnCl₂ is a Lewis acid: it turns OH into a better leaving group. - Works for alcohols soluble in the reagent (up to about six carbons). Drawn with 54 atoms, 7 arrows, 7 shapes – every one editable in MolDraw. ## Sources - [Furniss et al., Vogel's Textbook of Practical Organic Chemistry, 5th ed., Longman 1989](https://openlibrary.org/isbn/9780582462366) Textbook - [Clayden, Greeves & Warren, Organic Chemistry, 2nd ed., OUP 2012](https://openlibrary.org/isbn/9780199270293) Textbook ## 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 Lucas test template free? You can preview the Lucas test 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 Lucas test 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. ### Which name reactions are included? 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