Molar Mass of Glucose (C₆H₁₂O₆)
Learn how chemists calculate the molar mass of Glucose (C₆H₁₂O₆), with a clear formula breakdown, worked steps, and study notes · IUPAC name: (2R,3R,4S,5S,6R)-6-(Hydroxymethyl)oxane-2,3,4,5-tetrol.
Quick answer
The molar mass of Glucose (C₆H₁₂O₆) is
180.156g/mol
One mole of Glucose therefore has a mass of 180.156 grams—the value you use for stoichiometry and laboratory preparation.
Reviewed for educational accuracy · Accuracy policy
- CAS Registry Number
- 50-99-7
- PubChem CID
- 5793
- SMILES
- C([C@@H]1[C@H]([C@@H]([C@H]([C@H](O1)O)O)O)O)O
Step-by-step calculation
Let's find the molar mass of Glucose (C₆H₁₂O₆) together—step by step, as if you are seeing the formula for the first time.
Step 1 — Look at the chemical formula
The formula is C₆H₁₂O₆. Each letter stands for an element. The little number after a letter (the subscript) tells you how many atoms of that element are in one molecule or formula unit.
- 6 Carbon atoms (C)
- 12 Hydrogen atoms (H)
- 6 Oxygen atoms (O)
Step 2 — Look up each atomic mass
Atomic mass comes from the periodic table. It is the average mass of one mole of atoms of that element, in grams per mole (g/mol). Think of it as the "price tag" for one mole of that element.
- Carbon (C) = 12.011 g/mol
- Hydrogen (H) = 1.008 g/mol
- Oxygen (O) = 15.999 g/mol
Step 3 — Multiply atoms × atomic mass
Why multiply? If one oxygen atom "costs" about 16 g/mol, then two oxygen atoms cost twice as much. Each element's contribution is: number of atoms × atomic mass.
- 6 × 12.011 = 72.066 g/mol (Carbon)
- 12 × 1.008 = 12.096 g/mol (Hydrogen)
- 6 × 15.999 = 95.994 g/mol (Oxygen)
Step 4 — Add the contributions
Why add? The molar mass of the whole compound is simply the total mass of every atom in the formula. Add each element's contribution:
72.066 + 12.096 + 95.994 = 180.156 g/mol
Step 5 — Final answer
Molar mass of Glucose = 180.156 g/mol
That means one mole of Glucose (C₆H₁₂O₆) has a mass of about 180.16 grams.
Quick summary
Read the formula → count atoms → look up atomic masses → multiply → add → report g/mol. For C₆H₁₂O₆, the total is 180.156 g/mol.
Common beginner mistakes
- Confusing glucose (monosaccharide) with table sugar sucrose (disaccharide).
- Forgetting that cyclic glucose has a hemiacetal, not a full acetal — hence reducing character.
- Using wrong molar mass when converting mg/dL to mmol/L in clinical problems.
Memory trick
Draw Haworth projection of β-D-glucopyranose — most stable chair conformation has all large groups equatorial.
Mini practice
Without looking above, list the atoms in C₆H₁₂O₆ and write one multiplication line for the heaviest element. Then check your work against Step 3.
Real-world example
If a recipe asks for 0.100 mol of Glucose, mass needed = 0.100 × 180.156 = 18.016 g. That is how chemists turn a mole amount into a weighable sample.
Atomic contribution table
Each row shows how much mass one element contributes to the total for C₆H₁₂O₆.
| Element | Atoms | Atomic mass | Contribution | Mass % |
|---|---|---|---|---|
| C | 6 | 12.011 | 72.066 g/mol | 40.0% |
| H | 12 | 1.008 | 12.096 g/mol | 6.7% |
| O | 6 | 15.999 | 95.994 g/mol | 53.3% |
| Total molar mass | 180.156 g/mol | 100% | ||
Mass contribution chart
Count every atom in this formula, multiply by atomic mass, then add. That total is the molar mass used in lab weighing.
Download study sheets
Save a printable summary, revision sheet, practice worksheet, or laboratory reference for Glucose (C₆H₁₂O₆).
Practice this calculation
Without looking above, write the atom count for C₆H₁₂O₆, then compute the molar mass. Check your answer against 180.156 g/mol.
Next challenge: how many grams are in 0.250 mol of Glucose? Multiply 0.250 × 180.156 to get 45.039 g.
Physical and chemical properties
Physical properties
| Appearance | White crystalline powder or odorless crystals |
| Color | White |
| Odor | Odorless |
| State (STP) | Solid |
| Density | 1.54 g/cm³ |
| Melting point | 146 °C (α-D-glucose, decomposes) |
| Boiling point | Decomposes before boiling |
| Solubility | 909 g/L water at 25 °C (very soluble) |
| Crystal structure | Monoclinic (α-D-glucose monohydrate) |
Chemical properties
| Classification | Monosaccharide / aldohexose / reducing sugar |
| Family | Carbohydrates (hexoses) |
| Polarity | Highly polar (multiple OH groups, hydrogen bonding) |
| Geometry | Pyranose ring (chair conformation in solution) |
| Oxidation states | Carbon varies; aldehyde carbon oxidized in reducing sugar tests |
Applications
Industrial uses
- High-fructose corn syrup production (glucose isomerized to fructose)
- Fermentation feedstock for bioethanol
- IV dextrose solutions in medical fluids
- Food sweetener and baking ingredient (dextrose)
Laboratory uses
- Cell culture media carbohydrate source
- Enzyme assay substrate (glucose oxidase/peroxidase kits)
- Demonstration of mutarotation and reducing sugar tests
Central metabolite in glycolysis (glucose → 2 pyruvate + 2 ATP + 2 NADH), gluconeogenesis, glycogen storage, and the pentose phosphate pathway for NADPH and ribose-5-phosphate.
Preparation and production
Industrial glucose is produced by acid or enzymatic hydrolysis of starch (corn, potato, wheat). Enzymatic routes use α-amylase and glucoamylase. Laboratory samples are purchased as D-(+)-glucose monohydrate or anhydrous reagent.
Global dextrose production exceeds 10 million tonnes, primarily from corn starch in the United States via wet milling.
Important reactions of Glucose
C₆H₁₂O₆ + 6 O₂ → 6 CO₂ + 6 H₂O
- Reaction type
- Cellular respiration (aerobic)
- Conditions
- Enzymes, mitochondria, aerobic conditions
- Explanation
- Complete oxidation of glucose yields CO₂ and water, releasing ~2870 kJ/mol energy, captured as ATP through glycolysis, Krebs cycle, and oxidative phosphorylation.
- Products
- Carbon dioxide and water
- Why it matters
- Metabolic energy production in all aerobic organisms
Related ideas: Bioenergetics · Redox · Metabolism
C₆H₁₂O₆ → 2 C₂H₅OH + 2 CO₂
- Reaction type
- Alcoholic fermentation
- Conditions
- Yeast (Saccharomyces), anaerobic, ~30–37 °C
- Explanation
- Zymase enzymes in yeast convert glucose to ethanol and CO₂ when oxygen is absent, regenerating NAD⁺ for continued glycolysis.
- Products
- Ethanol and carbon dioxide
- Why it matters
- Brewing, winemaking, biofuel production
Related ideas: Fermentation · Anaerobic metabolism · Enzyme catalysis
C₆H₁₂O₆ + 2 Cu²⁺ (alkaline) → C₆H₁₂O₇ + Cu₂O(s) + ...
- Reaction type
- Redox (Benedict's test)
- Conditions
- Alkaline copper(II) tartrate, heat
- Explanation
- Glucose reduces Cu²⁺ to Cu₂O (brick-red precipitate); the aldehyde group is oxidized to a carboxylic acid.
- Products
- Gluconic acid (or gluconate) and copper(I) oxide
- Why it matters
- Qualitative test for reducing sugars, clinical urinalysis (historical)
Related ideas: Reducing sugars · Qualitative analysis · Redox titrations
n C₆H₁₂O₆ → (C₆H₁₀O₅)ₙ + n H₂O
- Reaction type
- Polymerization (glycogen/starch formation)
- Conditions
- Glycogen synthase, UDP-glucose, liver/muscle cells
- Explanation
- Glucose units link via α-1,4 and α-1,6 glycosidic bonds to form glycogen for energy storage in animals.
- Products
- Glycogen polymer
- Why it matters
- Energy storage in liver and skeletal muscle
Related ideas: Polymerization · Glycosidic bonds · Biochemistry
History and discovery
Andreas Marggraf extracted glucose from raisins in 1747. Emil Fischer determined the stereochemistry of sugars in the 1890s, earning the Nobel Prize (1902) and establishing the Fischer projection notation still used today.
Andreas Marggraf, 1747 — crystallized sweet substance from grape juice and raisins, later identified as glucose.
Interesting facts
- Glucose was named from Greek gleukos (sweet wine); isolated from raisins by Marggraf (1747).
- Mutarotation: fresh α-glucose solution [α]D = +112°, equilibrates to +52.7° as β-anomer dominates (~64%).
- Brain consumes roughly 120 g glucose daily, almost entirely from blood supply.
- The molar mass 180.16 g/mol means 180 mg = 1 mmol, a useful clinical conversion.
Comparison with similar compounds
Glucose and fructose share C₆H₁₂O₆ (180.16 g/mol) but differ in function: glucose is an aldose prioritized for glycolysis; fructose is a ketose metabolized primarily in the liver.
Storage, handling, and safety
Store desiccated in sealed containers; glucose is hygroscopic. Protect from microbial contamination in aqueous solutions — glucose supports bacterial growth readily.
Low acute toxicity. Powder may create dust; avoid inhalation. Sterile technique for medical and cell culture applications.
Safe food ingredient; primary concern is dietary glycemic impact in diabetes management, not acute chemical toxicity.
- Dust inhalation irritation
- Microbial growth in aqueous glucose solutions
- Hyperglycemia from excessive IV infusion (medical context)
Classification: GRAS (Generally Recognized as Safe) for food use
Exam notes and student tips
Exam notes
- Molar mass C₆H₁₂O₆ = 6(12.01) + 12(1.008) + 6(16.00) = 180.16 g/mol.
- Glucose is a reducing sugar — gives positive Benedict's test.
- Glycolysis: C₆H₁₂O₆ + 2 NAD⁺ + 2 ADP + 2 Pi → 2 pyruvate + 2 NADH + 2 ATP + 2 H₂O (net).
- Distinguish glucose from sucrose (non-reducing disaccharide, M = 342.30 g/mol).
Student tips
- Draw Haworth projection of β-D-glucopyranose — most stable chair conformation has all large groups equatorial.
- Remember 180 g/mol ≈ 180 mg/mmol for quick blood glucose unit conversions.
- Link reducing sugar tests to the open-chain aldehyde form.
Common mistakes
- Confusing glucose (monosaccharide) with table sugar sucrose (disaccharide).
- Forgetting that cyclic glucose has a hemiacetal, not a full acetal — hence reducing character.
- Using wrong molar mass when converting mg/dL to mmol/L in clinical problems.
Misconceptions
- Glucose and fructose are not identical — fructose is a ketohexose (C₆H₁₂O₆, same molar mass, different structure).
- All sugars are not reducing sugars; sucrose lacks a free anomeric OH.
- Blood glucose is not the same as dietary glucose absorption rate — starch must be hydrolyzed first.
Practice questions
1. Calculate the molar mass of glucose (C₆H₁₂O₆).
Show answer
6(12.01) + 12(1.008) + 6(16.00) = 180.16 g/mol
2. A patient has blood glucose of 180 mg/dL. Convert to mmol/L.
Hint: Use molar mass 180.16 g/mol = 180.16 mg/mmol.
Show answer
180 mg/dL = 1800 mg/L; 1800 mg ÷ 180.16 mg/mmol = 10.0 mmol/L
3. Why does glucose give a positive Benedict's test but sucrose does not?
Show answer
Glucose has a free anomeric OH (hemiacetal) that opens to an aldehyde; sucrose has both anomeric carbons tied up in glycosidic linkage.
4. How many moles of CO₂ from complete combustion of 360 g glucose?
Show answer
360 g ÷ 180.16 g/mol = 2.0 mol glucose; produces 6 × 2.0 = 12 mol CO₂
Frequently asked questions about Glucose
180.16 g/mol.
Chemistry of Glucose
The sections above give the number you need for calculations. Here we look more closely at how Glucose (C₆H₁₂O₆) behaves chemically—so the molar mass connects to real reactions, properties, and laboratory practice.
Glucose (C₆H₁₂O₆) is a monosaccharide with molar mass 180.16 g/mol, serving as the primary fuel molecule for cellular respiration in most organisms. Its open-chain form is an aldohexose: a six-carbon chain with an aldehyde at C1 and five hydroxyl groups. In aqueous solution, glucose predominantly cyclizes to a six-membered pyranose ring (glucopyranose), with α and β anomers interconverting via mutarotation through the open-chain aldehyde intermediate.
Blood glucose is tightly regulated in mammals between roughly 70–100 mg/dL (3.9–5.6 mM) in fasting humans. Insulin promotes cellular uptake and glycogen synthesis; glucagon and epinephrine raise blood glucose by stimulating glycogenolysis and gluconeogenesis. The molar mass 180.16 g/mol is essential for converting between mg/dL clinical units and SI mmol/L in medical biochemistry.
C₆H₁₂O₆ indicates six carbon, twelve hydrogen, and six oxygen atoms. The ratio 1:2:1 (C:H:O) matches the general formula for carbohydrates Cₙ(H₂O)ₙ, historically suggesting "hydrates of carbon." Each carbon except the primary alcohol carbon (C6) bears a hydroxyl group, giving rise to stereoisomerism — D-glucose is one of sixteen aldohexose stereoisomers.
Glucose is a reducing sugar: the hemiacetal at C1 can open to expose an aldehyde that reduces Cu²⁺ in Benedict's or Fehling's reagent to Cu₂O. It undergoes fermentation by yeast to ethanol and CO₂, esterification of hydroxyls, and glycosidic bond formation when condensed with another monosaccharide (e.g., maltose, lactose). With concentrated H₂SO₄ it chars; with HI and heat it can be reduced to hexane in classical degradation studies.
Photosynthesis: The Origin of Glucose
Plants, algae, and cyanobacteria build glucose from CO₂ and water using light energy captured by chlorophyll: 6 CO₂ + 6 H₂O + light → C₆H₁₂O₆ + 6 O₂. This reaction is the exact reverse of aerobic respiration and is the ultimate energy-capturing step that supplies, directly or indirectly, nearly all of the chemical energy used by life on Earth.
Cellular Respiration and ATP Yield
Complete aerobic oxidation of one mole of glucose through glycolysis, the citric acid cycle, and oxidative phosphorylation yields roughly 30–32 mol ATP (textbooks historically cited 36–38, since revised downward with more accurate proton-leak accounting), far more energy than anaerobic glycolysis alone (2 mol ATP), which is why muscle cells switch to lactic acid fermentation only when oxygen is limited.
Blood Sugar Regulation and Diabetes
Insulin and glucagon maintain blood glucose within a narrow range by promoting cellular uptake/glycogen storage or triggering glycogen breakdown and gluconeogenesis, respectively. In diabetes mellitus, insufficient insulin action (Type 1) or insulin resistance (Type 2) disrupts this balance, causing chronic hyperglycemia that is monitored clinically using glucose's precise molar mass (180.16 g/mol) to convert between mg/dL and mmol/L units.
Glucose vs. Sucrose in Food Chemistry
Sucrose (table sugar, C₁₂H₂₂O₁₁, 342.30 g/mol) is a disaccharide of glucose and fructose joined by a glycosidic bond that ties up both anomeric carbons, making it a non-reducing sugar unlike free glucose. Digestive enzymes (sucrase) must hydrolyze sucrose back into glucose and fructose before the body can absorb and metabolize the individual monosaccharides.
Glycemic Index and Food Science
Different carbohydrate-containing foods raise blood glucose at different rates depending on their starch structure, fiber content, and processing — quantified by the glycemic index (GI), with pure glucose defined as the GI = 100 reference point against which other foods are compared in nutrition science.
Recalculate any formula with the molar mass calculator, compare atoms on the periodic table, or browse more compounds in the organic library.
References and further reading
- IUPAC: Carbohydrate nomenclature and stereochemistry
- PubChem CID 5793: Glucose structure and properties
- Lehninger Principles of Biochemistry: Glycolysis and glucose metabolism