Acid and Base Theory
- S-1-Pharmaceutical Inorganic Chemistry
- Feb 26
- 1 min read
Updated: Mar 2
Buy Now the Hard Copy of notes for seamless and ad-free learning, Click Below!
1) Arrhenius Concept of (Acid and Base Theory)
Acids: Substances that dissociate in water to produce hydrogen ions (H⁺).
Bases: Substances that dissociate in water to produce hydroxide ions (OH⁻).
Example
Acid: HCl(aq) → H⁺(aq) + Cl⁻(aq)
Base: NaOH(aq) → Na⁺(aq) + OH⁻(aq)
Neutralization reaction: HCl(aq) + NaOH(aq) → H₂O(l) + NaCl(aq)
Limitations
Only applies to aqueous solutions.
Does not explain non-aqueous or gas-phase reactions.
Cannot account for substances without H⁺ or OH⁻ ions.
2) Bronsted-Lowry Concept
Acids: Proton (H⁺) donors.
Bases: Proton (H⁺) acceptors.
Example
Acid: H₂O(l) + NH₃(aq) ⇌ OH⁻(aq) + NH₄⁺(aq)
Base: NH₃(aq) + H₂O(l) ⇌ NH₄⁺(aq) + OH⁻(aq)
Conjugate acid-base pairs: NH₄⁺/NH₃ and H₂O/OH⁻
Advantages
Applicable to both aqueous and non-aqueous solutions.
Explains acidic or basic behavior of substances without H⁺ or OH⁻ ions.
Limitations
It does not explain the acid-base behavior of substances that do not involve proton transfer.
It does not account for reactions where electron pairs play a significant role.
3) Lewis Concept
Acids: Electron-pair acceptors.
Bases: Electron-pair donors
Example
Lewi's acid: BF₃ + F⁻ → BF₄⁻
Lewi's base: F⁻ + BF₃ → BF₄⁻
Advantages
Applies to a wide range of reactions, including non-proton-transfer processes.
Covers reactions in all phases (gas, liquid, solid) and solvents.
Limitations
Can be too broad, classifying non-traditional acids/bases.
More abstract and less intuitive than other concepts of Acid and Base Theory
Buy Now the Hard Copy of notes for seamless and ad-free learning, Click Below!
