Molecular formula
Citric Acid
C₆H₈O₇
Lactic Acid
C₃H₆O₃
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Citric Acid vs Lactic Acid
| Property | Citric Acid | Lactic Acid |
|---|---|---|
| Molecular formula | C₆H₈O₇ | C₃H₆O₃ |
| CAS identity | 77-92-9 | 50-21-5 |
| Molecular weight | 192.12 g/mol | 90.08 g/mol |
| Carbon atoms | 6 | 3 |
| Carboxyl groups | 3 | 1 |
| Structure | HOOC–CH₂–C(OH)(COOH)–CH₂–COOH | CH₃–CH(OH)–COOH |
| Family | Hydroxytricarboxylic acid | Hydroxymonocarboxylic acid |
| Additional hydroxyl | Present | Present |
| Aromatic ring | Absent | Absent |
| Stereochemical context | Achiral molecular structure | Chiral molecular structure; product stereochemical form must be specified |
| Profile / product form | Solid · anhydrous identity | Commercial liquids / aqueous solutions |
| pKa with conditions | 3.128 / 4.761 / 6.396 (25 °C, water, zero ionic strength)Reference and conditions | 3.86 (20 °C, in water)Reference and conditions |
| Solubility & thermal reference | Review conditions and chemical form | Review conditions and chemical form |
| Application notes | Citric Acid uses and derivative distinctions | Lactic Acid uses and derivative distinctions |
| Buying specification | Specify anhydrous or monohydrate, assay basis, and the required application specification. | Specify concentration, chemical assay and method, L/D/DL form, optical specification, water content, and package mass or volume separately. |
| Identity source | Citric Acid identity record | Lactic Acid identity record |
CAS identity
Citric Acid
77-92-9
Lactic Acid
50-21-5
Molecular weight
Citric Acid
192.12 g/mol
Lactic Acid
90.08 g/mol
Carbon atoms
Citric Acid
6
Lactic Acid
3
Carboxyl groups
Citric Acid
3
Lactic Acid
1
Structure
Citric Acid
HOOC–CH₂–C(OH)(COOH)–CH₂–COOH
Lactic Acid
CH₃–CH(OH)–COOH
Family
Citric Acid
Hydroxytricarboxylic acid
Lactic Acid
Hydroxymonocarboxylic acid
Additional hydroxyl
Citric Acid
Present
Lactic Acid
Present
Aromatic ring
Citric Acid
Absent
Lactic Acid
Absent
Stereochemical context
Citric Acid
Achiral molecular structure
Lactic Acid
Chiral molecular structure; product stereochemical form must be specified
Profile / product form
Citric Acid
Solid · anhydrous identity
Lactic Acid
Commercial liquids / aqueous solutions
pKa with conditions
Citric Acid
3.128 / 4.761 / 6.396 (25 °C, water, zero ionic strength)Reference and conditions
Lactic Acid
3.86 (20 °C, in water)Reference and conditions
Solubility & thermal reference
Citric Acid
Lactic Acid
Application notes
Citric Acid
Lactic Acid
Buying specification
Citric Acid
Specify anhydrous or monohydrate, assay basis, and the required application specification.
Lactic Acid
Specify concentration, chemical assay and method, L/D/DL form, optical specification, water content, and package mass or volume separately.
Identity source
Citric Acid
Lactic Acid
No differences remain for these selections. Choose another acid or show all fields.
Numerical pKa values are repeated here only for the six independently reviewed profiles, with their reference conditions. Other values remain in the individual technical references. Compare matched identities and conditions; no acidity ratio or solubility ranking is inferred.
3 CARBOXYL GROUPS · 6 CARBONS
Citric Acid
Hydroxytricarboxylic acid
Three carboxyl groups and one additional hydroxyl group.
1 CARBOXYL GROUP · 3 CARBONS
Lactic Acid
Hydroxymonocarboxylic acid
A three-carbon alpha-hydroxy acid; L, D and DL forms matter.
Why Compare These Acids?
Malonic Acid vs Succinic Acid
A methylene spacer changes the carbon framework while both retain two carboxyl groups.
Compare these acids →Citric Acid vs Malic Acid
Three versus two carboxyl groups, with different hydroxy-acid frameworks.
Compare these acids →Benzoic Acid vs Salicylic Acid
See what the adjacent phenolic hydroxyl adds to an aromatic carboxyl structure.
Compare these acids →Acetic Acid vs Formic Acid
Compare the two-carbon acid with the one-carbon member of the family.
Compare these acids →Propionic Acid vs Butyric Acid
Compare adjacent members of the straight-chain monocarboxylic series.
Compare these acids →Fumaric Acid vs Succinic Acid
Contrast an E/trans double bond with a saturated four-carbon chain.
Compare these acids →Lactic Acid vs Citric Acid
One versus three carboxyl groups; stereochemistry and solution specifications also differ.
Compare these acids →Tartaric Acid vs Malic Acid
Two versus one hydroxyl-bearing stereocenters, with different profile stereochemical identities.
Compare these acids →More Structural Comparisons
Oxalic Acid vs Malonic Acid
Directly joined carboxyl carbons versus a methylene spacer.
Compare these acids →Succinic Acid vs Adipic Acid
A longer saturated diacid framework changes the structural comparison.
Compare these acids →Lactic Acid vs Malic Acid
An alpha-hydroxy monoacid versus a hydroxy diacid.
Compare these acids →Mandelic Acid vs Lactic Acid
A phenyl group versus a methyl group in an alpha-hydroxy acid.
Compare these acids →Benzoic Acid vs Mandelic Acid
A ring-bound carboxyl versus a hydroxyl-bearing side chain.
Compare these acids →Salicylic Acid vs Mandelic Acid
Compare a phenolic hydroxyl on the ring with an alpha hydroxyl on the side chain.
Compare these acids →Pentanoic Acid vs Butyric Acid
One carboxyl group terminates a four-carbon alkyl chain. The carboxyl carbon brings the total to five; branched valeric-acid isomers are different compounds.
Compare these acids →Hexanoic Acid vs Octanoic Acid
The structure is a five-carbon alkyl chain joined to COOH. It has neither an additional hydroxyl group nor a carbon–carbon double bond.
Compare these acids →Heptanoic Acid vs Hexanoic Acid
Its six-carbon alkyl group ends in one carboxyl group. It is achiral and has no geometric double-bond isomer to specify.
Compare these acids →Nonanoic Acid vs Octanoic Acid
The molecule contains eight alkyl-chain carbons and one carboxyl carbon. Nonanoate salts, including ammonium nonanoate, are separate products.
Compare these acids →Decanoic Acid vs Octanoic Acid
Nine alkyl-chain carbons terminate in COOH. Capric acid is distinct from the eight-carbon caprylic acid and from caprate salts or esters.
Compare these acids →Acrylic Acid vs Methacrylic Acid
The terminal CH₂=CH group is attached to COOH. Because one alkene carbon carries two hydrogens, acrylic acid does not have an E/Z pair.
Compare these acids →Crotonic Acid vs Methacrylic Acid
The carbon–carbon double bond lies between carbons 2 and 3. E geometry places the higher-priority carboxyl and methyl groups on opposite sides; the condensed drawing alone does not encode that geometry.
Compare these acids →Sorbic Acid vs Benzoic Acid
Two carbon–carbon double bonds alternate with a single bond. Both double bonds have E geometry. Potassium sorbate is a salt with a different formula, molecular weight and commercial specification.
Compare these acids →Maleic Acid vs Fumaric Acid
Two carboxyl groups lie on the same side of the carbon–carbon double bond. Fumaric acid places them on opposite sides. The same formula and molecular weight do not establish interchangeable identity.
Compare these acids →Glutaric Acid vs Succinic Acid
Two terminal COOH groups flank a three-carbon methylene spacer. There is no additional hydroxyl group, carbon–carbon double bond or stereocenter in this free-acid identity.
Compare these acids →Pimelic Acid vs Adipic Acid
Two carboxyl groups terminate a chain containing five CH₂ groups. The neutral free acid is achiral and has no carbon–carbon double bond.
Compare these acids →Suberic Acid vs Pimelic Acid
Six methylene groups connect two terminal carboxyl groups. Octanedioic acid is the free acid; disuccinimidyl suberate is a chemically activated ester derivative.
Compare these acids →Azelaic Acid vs Sebacic Acid
Seven CH₂ groups separate its two carboxyl groups. There is no alkene or stereocenter in the neutral free-acid identity.
Compare these acids →Glycolic Acid vs Lactic Acid
The hydroxyl-bearing carbon is CH₂, so it has no stereocenter. The non-carboxylic OH makes this a hydroxy acid; it does not add a second carboxyl group.
Compare these acids →Pyruvic Acid vs Lactic Acid
A ketone carbonyl lies next to the carboxyl group. There is one COOH group and no stereocenter in the neutral molecular structure.
Compare these acids →Gluconic Acid vs Glycolic Acid
Four CHOH centers carry the stereochemistry of this D identity. The terminal CH₂OH supplies the fifth non-carboxylic hydroxyl. A condensed formula does not encode the four configurations; the IUPAC name and InChI do.
Compare these acids →Levulinic Acid vs Pyruvic Acid
Two CH₂ groups separate the carboxyl carbon from the ketone carbon. This is a gamma-keto acid, not the adjacent alpha-keto arrangement of pyruvic acid; the neutral identity is achiral.
Compare these acids →Phenylacetic Acid vs Benzoic Acid
The benzene ring makes this an aromatic-containing acid, but the carboxyl carbon is not attached directly to the ring. Its CH₂ side chain has no stereocenter.
Compare these acids →Cinnamic Acid vs Phenylacetic Acid
A CH=CH unit connects the phenyl ring to COOH. E describes the opposite-side arrangement of the higher-priority substituents across that double bond. This structure has no phenolic hydroxyl group.
Compare these acids →Phthalic Acid vs Isophthalic Acid
Two neighboring ring carbons carry COOH groups. Their adjacent arrangement is positional isomerism, not a cis/trans alkene designation. The neutral acid is achiral.
Compare these acids →Terephthalic Acid vs Isophthalic Acid
The 1,4, or para, arrangement is a molecular-connectivity identity. It is distinct from 1,2 phthalic acid and 1,3 isophthalic acid despite sharing their formula and molecular weight.
Compare these acids →3-Hydroxybenzoic Acid vs 4-Hydroxybenzoic Acid
COOH defines ring position 1 and OH occupies position 3. There is one carboxyl group, not two; the phenolic proton is a separate acid-base site. The neutral structure is achiral.
Compare these acids →Gallic Acid vs 4-Hydroxybenzoic Acid
OH groups occupy ring positions 3, 4 and 5. The neutral free acid is achiral; its formula excludes any crystal water. Three phenolic OH groups do not mean three COOH groups.
Compare these acids →Lauric Acid vs Myristic Acid
Ten methylenes lie between CH₃ and COOH. The chain is saturated and achiral, with no E/Z alkene identity.
Compare these acids →Palmitic Acid vs Stearic Acid
Fourteen methylenes connect CH₃ to COOH. C16:0 indicates 16 carbons and zero carbon–carbon double bonds. The neutral identity is achiral.
Compare these acids →Oleic Acid vs Linoleic Acid
Numbering from the carboxyl carbon places the double bond between C9 and C10. Z, or cis for this alkene, specifies the same-side higher-priority carbon chains. There is no stereocenter.
Compare these acids →Turn a Comparison Into a Specification
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