Buffers: Definition, Components, and pH Calculation
Definition
Buffers
Buffers are solutions that resist changes in pH when small amounts of acid ($H⁺$ ions) or base ($OH⁻$ ions) are added.
They play a critical role in maintaining pH stability in chemical reactions, biological systems (like blood), and industrial processes.
To understand how buffers work, consider this:
- If you add a strong acid to pure water, the pH drops significantly because there’s nothing in the water to counteract the influx of $H⁺$ ions.
- A buffer, however, "absorbs" most of these $H⁺$ ions, minimizing the pH change.
- Think of a buffer as a sponge.
- Just as a sponge absorbs water to prevent spills, a buffer absorbs excess $H⁺$ or $OH⁻$ ions, preventing drastic pH changes.
Components of a Buffer
Every buffer consists of two key components:
- A weak acid and its conjugate base(e.g., $CH₃COOH$/$CH₃COO⁻$).
- A weak base and its conjugate acid(e.g., $NH₃$/$NH₄⁺$).
