Sodium hydroxide vs Sodium bicarbonate: what is the difference?
Sodium bicarbonate is a weak alkali mild enough to eat, while sodium hydroxide is caustic soda, strong enough to dissolve fat and hair and corrosive to skin.
Sources and notes
- The sentence under the titlefrom sourceMoleculeFinder comparison notesThe pair's answer line.
- The two drawingscomputedMoleculeFinder rule (RDKit MCS)Each molecule's own drawing, as its page shows it. The common core, 0 of 4 atoms, is too small to align on.
Side by side
| Sodium hydroxide | Sodium bicarbonate | |
|---|---|---|
| Molecular weightCalculated PubChem | 40 g/molHNaO | 84.01 g/molCHNaO3 |
| Hydrogen-bond donorsCalculated PubChem | 1 | 1 |
| Where each turns upEditorial MoleculeFinder food and product lists |
|
|
| FamilyEditorial MoleculeFinder curated | Inorganic compounds | Other |
| Everyday groupEditorial MoleculeFinder curated | Everyday chemistry | Food & flavor |
| Hazard labelReported ECHA, EU CLP Regulation, Safe Work Australia via PubChem | Danger | Not recorded |
| The supplier-filed hazard label's signal word, not a statement about ordinary use. | ||
| LD50Measured HSDB via PubChem | 40 mg/kgpure sodium hydroxide, mouse, another route | 4,220 mg/kgpure sodium bicarbonate, rat, oral |
| A single acute animal measure, here in two different species. It ranks nothing about human safety. | ||
Sources and notes
- Molecular weightcomputedPubChemComputed from the structure; the formula is under each weight.
- Hydrogen-bond donorscomputedPubChemThe hydrogens on nitrogen or oxygen that each molecule can lend to a hydrogen bond, counted from its structure.
- Where each turns upfrom sourceMoleculeFinder food and product listsEach amount is an editorial figure from our lists, not a measurement of any one product. Each mark is set by hand on the list, never inferred.
- Familyfrom sourceMoleculeFinder curated
- Everyday groupfrom sourceMoleculeFinder curated
- Hazard labelfrom sourceECHA, EU CLP Regulation, Safe Work Australia via PubChem
- LD50from sourceHSDB via PubChem
- ECHAfrom sourceAttributionSource: European Chemicals Agency, echa.europa.eu.
- EU CLP Regulationfrom sourceAttributionSource: EUR-Lex, Regulation (EC) No 1272/2008, © European Union.
- Safe Work Australiafrom sourceAttributionSource: Safe Work Australia, Hazardous Chemical Information System, © Commonwealth of Australia, CC BY 4.0.
- Identifiersfrom sourcePubChemPubChem CID 14798 (Sodium hydroxide) and 516892 (Sodium bicarbonate).
In more detail
Both are alkaline and they sit at opposite ends of that scale. Sodium bicarbonate is weak enough to eat and is used to neutralise acid in a stomach or a recipe. Sodium hydroxide is caustic soda, strong enough to saponify fat and dissolve hair, which is what makes it the active ingredient in drain cleaner and in soap making. The GHS classifications say it plainly: sodium hydroxide carries the corrosive pictogram and bicarbonate does not. Weights are close at 40.0 and 84.01, which is a reminder that molecular size says nothing about hazard. Sodium hydroxide releases significant heat when it dissolves, and bicarbonate does not.
Sources and notes
- The paragraphfrom sourceMoleculeFinder comparison notes
Questions
- What is the difference between Sodium hydroxide and Sodium bicarbonate?
- Sodium bicarbonate is a weak alkali mild enough to eat, while sodium hydroxide is caustic soda, strong enough to dissolve fat and hair and corrosive to skin.
- Is Sodium hydroxide bigger than Sodium bicarbonate?
- Sodium bicarbonate is the heavier molecule, 84.01 g/mol against 40 g/mol for Sodium hydroxide. Sodium hydroxide is HNaO and Sodium bicarbonate is CHNaO3.
Sources and notes
- The answersfrom sourceMoleculeFinderThe first is the pair's answer line; the others are read off the table above.