A buffer contains significant amounts of ammonia and ammonium chloride. Write equations showing how this buffer neutralizes added acid and added base.

Key Concepts

Buffer Solutions

Buffer solutions are mixtures that resist changes in pH when small amounts of acid or base are added. They typically consist of a weak acid and its conjugate base or a weak base and its conjugate acid. In this case, ammonia (NH3) acts as the weak base, while ammonium chloride (NH4Cl) provides the conjugate acid (NH4+).

Neutralization Reactions

Neutralization reactions occur when an acid reacts with a base to form water and a salt. In the context of a buffer, when an acid is added, the weak base (NH3) will react with the hydrogen ions (H+) from the acid, effectively neutralizing it. Conversely, when a base is added, the conjugate acid (NH4+) will react with the hydroxide ions (OH-) to maintain the pH.

Equilibrium in Buffer Systems

Buffer systems operate based on the principle of chemical equilibrium, where the concentrations of the weak acid and its conjugate base (or weak base and its conjugate acid) adjust to counteract changes in pH. The equilibrium shifts in response to added acids or bases, allowing the buffer to maintain a relatively stable pH, which is crucial for many biological and chemical processes.