Terephthalic Acid 3D Model — CAS 100-21-0

Terephthalic Acid (C8H6O4, CAS 100-21-0) — a free educational 3D molecular model for teachers and students, by MolGod.org. No legend required: the element symbol is engraved on each atom. Let the group sketch what they see in Terephthalic Acid, namely one aromatic 6-membered ring; afterwards they compare the sketch with the 18 bonds on the model (10 single, 2 double and 6 aromatic, drawn in Kekulé form). Counting task: 8 C + 6 H + 4 O gives 18 engraved spheres; can the class rebuild the formula C8H6O4 from the model alone? On the printed model, students can point to the two carboxylic acid groups (-COOH). Plan it into a unit on aromaticity and delocalised electrons, as well as on the carbonyl group (C=O). Students can compare it with Isophthalic Acid (CAS 121-91-5) and Phthalic Acid (CAS 88-99-3): identical molecular formula, different arrangement of atoms. Free for education: MolGod.org publishes engraved molecular models for teachers, students and schools. Teachers: let students set the model beside a skeletal formula and list what the drawing omits. Full record and more free models: https://molgod.org/molecule/100-21-0/?utm_source=thingiverse&utm_medium=referral&utm_campaign=edu-3d-models Licence & provenance: https://molgod.org/licenses/stl/100-21-0/ Same file on Wikimedia Commons: https://commons.wikimedia.org/wiki/File:Terephthalic_Acid-3D-molecular-model-engraved-CAS-100-21-0.stl A ball-and-stick model of Terephthalic Acid with each element symbol recessed into its atom sphere, generated by MolGod.org from a PubChem-computed 3D conformer (not an experimental crystal structure); atomic coordinates and connectivity are unchanged. STL mesh: 259,018 triangles, closed (watertight) single solid. Coordinates in ångström (STL stores no unit) — scale the model deliberately in your slicer. Names in other languages: Terephthalsäure (de); acide téréphtalique (fr); acido tereftalico (it); tereftaalzuur (nl); kwas tereftalowy (pl); 对苯二甲酸 (zh). Chemical identity - CAS Registry Number: 100-21-0 - Molecular formula: C8H6O4 - Molar mass: 166.13 g/mol (exact mass 166.02660867) - IUPAC name: terephthalic acid - MolGod ID: MG_864-993-681-12 (https://molgod.org/id/MG_864-993-681-12) - PubChem CID: 7489 (https://pubchem.ncbi.nlm.nih.gov/compound/7489) - Wikidata: Q408984 (https://www.wikidata.org/wiki/Q408984) - EC number: 202-830-0 - ChemSpider ID: 7208 - InChIKey: KKEYFWRCBNTPAC-UHFFFAOYSA-N - SMILES: C1=CC(=CC=C1C(=O)O)C(=O)O

Required attribution (CC BY-SA 4.0): "Terephthalic Acid 3D model by MolGod.org — https://molgod.org/molecule/100-21-0/ — CC BY-SA 4.0" Licence text: https://creativecommons.org/licenses/by-sa/4.0/