Syrabasbufferten

Syrabasbufferten, typically referred to in English as an acid–base buffer, is a solution that resists changes in pH when small amounts of acid or base are added. It achieves this stability by containing a weak acid and its conjugate base, or a weak base and its conjugate acid, which participate in reversible chemical equilibria.

Mechanism: The equilibrium HA ⇌ H+ + A− allows the buffer to absorb added protons by shifting toward HA, and to neutralize added hydroxide by forming A−. The result is a subdued change in pH. Buffer capacity depends on the total concentration of buffering species and on the ratio [A−]/[HA], with the most efficient buffering near the pKa of the acid.

Common buffer systems include acetic acid/acetate (pKa ≈ 4.76), phosphate buffers H2PO4−/HPO4^2− (pKa ≈ 7.21), and the bicarbonate system H2CO3/HCO3− (pKa ≈ 6.35). In biological contexts, buffers maintain pH in tissues and fluids; the bicarbonate system is especially important for blood pH, while cellular environments rely on phosphate and protein buffers.

Practical notes: optimal buffering occurs within about one pH unit of the buffer’s pKa. Buffer capacity increases with the total concentration of buffering species but can be affected by temperature and ionic strength, which can shift pKa values and alter performance. Syrabasbufferten is widely used in chemistry, biology, medicine, and environmental science to stabilize pH during experiments and processes.