Acetic acid molecule in 3D
C₂H₄O₂ · The carboxyl group in vinegar. Dilute acetic acid gives vinegar its characteristic acidity. Acetic acid is also a chemical manufacturing feedstock. Explore the 3D model, inspect its parts and learn with guided explanations. Free on Atlas.
What you can learn
C₂H₄O₂ · The carboxyl group in vinegar. Dilute acetic acid gives vinegar its characteristic acidity. Acetic acid is also a chemical manufacturing feedstock.
Count the 8 atoms. Match their element colours to the formula C₂H₄O₂.
Select a bond and identify the two atoms it connects. The carboxyl group contains a carbonyl C=O and a C–O–H connection. The two oxygen atoms do not have identical roles in the neutral acid.
Rotate the model to the side. The methyl carbon has approximately tetrahedral geometry. The carbon in the carboxyl group is approximately trigonal planar.
Explain the difference between the atoms present and the molecule they form. Acetic acid can donate a proton from its –OH group in water, producing acetate. That acid–base change is different from removing a proton from a nucleus.
Connect the model to daily life. Dilute acetic acid gives vinegar its characteristic acidity. Acetic acid is also a chemical manufacturing feedstock.
What is missing from a ball-and-stick picture? Consider electron density, movement and interactions with nearby molecules.
Try an investigation
Count the 8 atoms. Match their element colours to the formula C₂H₄O₂.
Check your understanding
How many atoms are in one C₂H₄O₂ molecule?
8. Add the atom counts in C₂H₄O₂: one molecule contains 8 atoms. Subscripts belong to the element or group immediately before them.
How many different elements make up C₂H₄O₂?
3. Acetic acid contains oxygen and carbon and hydrogen. Count element types separately from the total atom count.
What is the local geometry around the methyl carbon?
Tetrahedral. The methyl carbon has approximately tetrahedral geometry. The carbon in the carboxyl group is approximately trigonal planar.
Which group is present in acetic acid?
A –COOH carboxyl group. The carboxyl group contains a carbonyl C=O and a C–O–H connection. The two oxygen atoms do not have identical roles in the neutral acid.
What can the acid donate in an acid–base reaction?
A proton from the –OH group. Acetic acid can donate a proton from its –OH group in water, producing acetate. That acid–base change is different from removing a proton from a nucleus.
What do the sticks in this acetic acid model represent?
Chemical connections between atoms. Ball-and-stick models help compare connections and spatial arrangement. Real molecules have electron distributions and vibrating nuclei, not coloured balls joined by rods.
Sources and model scope
Atomic centres use a PubChem computed 3D conformer, scaled for display.