Inorganic · Acids, Bases & HSAB

Acids, Bases & the HSAB Principle

CSIR-NET Chemical Sciences revision note · 10 sections · about 914 words

Exam-focused revision notes on Acids, Bases & the HSAB Principle for CSIR-NET Chemical Sciences, GATE Chemistry and IIT-JAM — the core concepts, the formulas worth memorising, the traps that cost marks, and a quick-recall table.

The big picture

“Acid” and “base” have several definitions, each broader than the last. The exam tests which definition applies to a given reaction, how to pair conjugate acids and bases, and — most heavily — the HSAB principle for predicting which acid–base combinations are stable.

What this note covers

  • 1The big picture
  • 2Arrhenius concept
  • 3Brønsted–Lowry concept
  • 4Lewis concept
  • 5Lux–Flood concept
  • 6Solvent-system concept
  • 7HSAB principle (Hard & Soft Acids and Bases)
  • 8Superacids
  • 9Common traps students miss
  • 10Summary table — hard vs soft

Read the full note

The remaining 9 sections — including the worked examples, the common-traps list and the quick-recall table — are part of ChemVidya Full Access, along with 6,000+ practice questions.

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