Amphoterism
| Formula / Notation | Al₂O₃ + 6HCl → 2AlCl₃ + 3H₂O; Al₂O₃ + 2NaOH + 3H₂O → 2Na[Al(OH)₄] |
|---|---|
| Also Known As | Amphiprotic behaviour (for proton transfer), amphoteric character, acid-base duality |
What is Amphoterism?
Amphoterism is the property of a substance to react both as an acid and as a base. Amphoteric substances can neutralise both acids and bases. Examples include aluminium hydroxide Al(OH)₃, which dissolves in acid to form Al³⁺ ions and in strong alkali to form aluminate ions, and zinc oxide ZnO. Water is also amphoteric.
Formula & Notation
Other Names / Synonyms: Amphiprotic behaviour (for proton transfer), amphoteric character, acid-base duality
Properties & Characteristics
Uses & Applications
Safety Information
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
Key Facts
Frequently Asked Questions
Amphoterism is the property of a substance to react both as an acid and as a base. Amphoteric substances can neutralise both acids and bases. Examples include aluminium hydroxide Al(OH)₃, which dissolves in acid to form Al³⁺ ions and in strong alkali to form aluminate ions, and zinc oxide ZnO. Water is also amphoteric.
Amphoteric aluminium oxide (alumina) is used as a catalyst support, in chromatography, and in refractory materials. Zinc oxide's amphoteric nature is exploited in galvanising and sunscreen formulations. Amphoterism is fundamental in understanding corrosion of metals like aluminium in both acidic and…
Amphoteric metal hydroxides themselves are typically low-hazard solids. The reagents used to demonstrate amphoterism (concentrated acids and strong bases like NaOH) are corrosive and require eye protection, gloves, and appropriate ventilation.
The formula or notation for Amphoterism is: Al₂O₃ + 6HCl → 2AlCl₃ + 3H₂O; Al₂O₃ + 2NaOH + 3H₂O → 2Na[Al(OH)₄]