What Is the Molar Mass of C6H10O4? | The Exact Number

The molar mass of C6H10O4, the molecular formula for adipic acid, is 146.14 grams per mole (rounded).

If you’ve ever stared at a chemistry homework problem asking for the molar mass of C6H10O4, your first move might be counting atoms. Six carbons, ten hydrogens, four oxygens — that’s fourteen atoms to add up. The calculation looks straightforward, yet one small slip with a subscript or an atomic mass can send the answer off track.

The compound C6H10O4 is best known as adipic acid, a six-carbon dicarboxylic acid used in nylon production and as a food acidulant. Its molar mass is a fixed constant reported by several government databases — good news for anyone who needs a reliable number for stoichiometry or lab work.

What Is C6H10O4 Exactly?

The molecular formula C6H10O4 belongs to a handful of organic compounds. The most common, by far, is adipic acid — also called hexanedioic acid by its IUPAC name. It has a palindrome-like structure: two carboxyl groups (–COOH) at the ends of a four‑carbon chain.

Other compounds share the same formula, including aceburic acid and conduritol, but adipic acid is the one you’ll meet most often in chemistry courses and industrial chemistry. Its CAS number is 124‑04‑9, and it appears in everything from synthetic fibers to baking powder.

Why Students Miscalculate This Molar Mass

The math itself is simple multiplication and addition. Most errors come from small oversights. Here are the common traps:

• Misreading the subscripts: C6H10O4 means six carbon atoms, ten hydrogen, and four oxygen. It’s easy to read the 4 on oxygen as the total number of atoms and forget the 10 hydrogen — or vice versa.
• Using rounded atomic masses too early: If you round each element’s contribution before adding, the total can drift. Keep at least two decimal places until the final sum.
• Confusing molecular with empirical formula: The empirical formula C3H5O2 is a reduced ratio; its mass is about half the molecular mass. Using it as the molar mass gives an answer that’s too low.
• Forgetting to multiply by the element count: Each atomic mass must be multiplied by the number of atoms of that element. A single missed step — like using 12.01 for carbon instead of 12.01 × 6 — throws off the total by a lot.

Once you know these patterns, the calculation becomes nearly foolproof. The key is methodical work and a check against a trusted reference.

Step‑by‑Step Calculation of the Molar Mass

To compute the molar mass of adipic acid, start with the standard atomic masses (rounded to two decimals for classroom use): carbon 12.01 g/mol, hydrogen 1.01 g/mol, oxygen 16.00 g/mol. Multiply each by its subscript: carbon 12.01 × 6 = 72.06; hydrogen 1.01 × 10 = 10.10; oxygen 16.00 × 4 = 64.00. Add them: 72.06 + 10.10 + 64.00 = 146.16 g/mol. Using more precise values (carbon 12.011, hydrogen 1.008, oxygen 15.999) gives 146.14 g/mol.

The NIST molecular weight for hexanedioic acid is 146.1412 g/mol, which accounts for natural isotopic abundances. The small difference between 146.14 and 146.1412 is negligible for most homework and lab reports, but it’s the gold standard for precise work.

The Empirical Formula Connection

Every molecular formula has a reduced form called the empirical formula. For C6H10O4, the greatest common factor is 2, so dividing each subscript by 2 gives C3H5O2. That represents the simplest whole‑number ratio of atoms in adipic acid.

1. Identify the common factor: 6, 10, and 4 are all divisible by 2.
2. Divide each subscript by 2: C3H5O2.
3. Check the masses: The empirical molar mass is roughly half the molecular mass — about 73 g/mol — because the molecular formula is exactly twice the empirical formula. That ratio confirms the molecular formula is (C3H5O2)₂.

The empirical formula is useful for finding composition by mass and for identifying unknown compounds through elemental analysis.

Trusted Sources for Adipic Acid Data

Several authoritative databases report consistent molar masses. PubChem, maintained by the National Institutes of Health, lists the molecular weight as 146.14 g/mol. The NIST Chemistry WebBook provides the more precise value of 146.1412 g/mol, along with the IUPAC InChI and mass spectrum data.

The Adipic Acid Hexanedioic Acid entry on PubChem also includes the SMILES notation, the exact mass (146.057909 Da), and the monoisotopic mass. Fisher Scientific independently reports 146.142 g/mol. All three sources agree within 0.002 g/mol — strong evidence that the constant is reliable.

This pattern shows that each additional CH₂ group adds roughly 14 g/mol. Adipic acid sits at the end of a homologous series of straight‑chain dicarboxylic acids.

The Bottom Line

The molar mass of C6H10O4 — adipic acid — is 146.14 g/mol, a constant backed by multiple independent government databases. Whether you’re balancing an equation, preparing a solution, or checking a lab result, that number is your anchor. The empirical formula C3H5O2 serves as a useful check, and step‑by‑step multiplication from atomic masses confirms the answer every time.

For homework or exam problems, pay attention to the atomic mass values your textbook or instructor uses; slight rounding differences (like using 12.00 for carbon instead of 12.01) can shift the final total by a few hundredths of a gram per mole. Always double‑check with a reliable periodic table or a source like the NIST WebBook to keep your results accurate.