What is a buffer solution?

A buffer solution is a mixture of a weak acid and its conjugate base (or weak base and conjugate acid). It resists changes in pH when small amounts of acid or base are added, which is critical in biological systems like blood.

Back to Chemistry Hub

Core Study Guide

Acids, Bases & Salts

Proton transfer, pH scale, and neutralization reactions.

Acids release hydrogen ions in water; bases release hydroxide ions or accept protons. Neutralization yields salt and water.

This unit covers pH and pOH logarithmic scales, Arrhenius vs Bronsted definitions, indicators, and volumetric titration.

Key Takeaways

•pH is the negative logarithm of hydrogen ion concentration; pH < 7 is acidic, pH > 7 is basic.
•Strong acids and bases dissociate completely in aqueous solutions.
•Neutralization is a double displacement reaction forming neutral salts and water.

Core Concepts & Definitions

1pH Logarithmic Scale

Every 1-unit change in pH represents a 10-fold change in hydrogen ion concentration.

•pH = -log[H⁺].

•Neutral pH is exactly 7.0 at 25°C.

Quick Revision Notes

•Strong acids include HCl, HNO3, H2SO4. Strong bases include NaOH, KOH, Ca(OH)2.
•Neutralization reactions are always exothermic (release heat).