Acid
| Formula / Notation | HA → H⁺ + A⁻ (Arrhenius); HA + B → A⁻ + BH⁺ (Brønsted) |
|---|---|
| Also Known As | Arrhenius acid; Brønsted acid; proton donor; Lewis acid; protonic acid |
What is Acid?
An acid is a substance that donates protons (H⁺ ions) to a base (Brønsted–Lowry definition), accepts electron pairs (Lewis definition), or produces hydrogen ions in aqueous solution (Arrhenius definition). Acids have pH < 7 in aqueous solution, taste sour, turn blue litmus red, and react with bases to form salts and water.
Formula & Notation
Other Names / Synonyms: Arrhenius acid; Brønsted acid; proton donor; Lewis acid; protonic acid
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
An acid is a substance that donates protons (H⁺ ions) to a base (Brønsted–Lowry definition), accepts electron pairs (Lewis definition), or produces hydrogen ions in aqueous solution (Arrhenius definition). Acids have pH < 7 in aqueous solution, taste sour, turn blue litmus red, and react with bases to form salts and water.
Industrial chemical manufacturing; food preservation and flavouring (citric acid, acetic acid); digestion (hydrochloric acid in stomach); battery electrolytes (sulfuric acid); fertiliser production (phosphoric acid, nitric acid); cleaning agents
Many acids are corrosive — concentrated strong acids (H₂SO₄, HCl, HNO₃) cause severe chemical burns. Dilute acids are irritants. Always handle with gloves and goggles; add acid to water (never water to acid) to control heat of dilution. Store in corrosive-resistant containers away from bases.
The formula or notation for Acid is: HA → H⁺ + A⁻ (Arrhenius); HA + B → A⁻ + BH⁺ (Brønsted)