Final answer:
A buffer is a solution that resists sudden changes in pH by reacting with small amounts of acid or base. It is composed of a weak acid or base and its salt. Buffers are important for maintaining pH stability in biological systems.
Step-by-step explanation:
Buffers in Chemistry
A buffer is a solution that resists sudden changes in pH. It is composed of a weak acid or base and its salt. When small amounts of acid or base are added to a buffer solution, the buffer's components react with the added acid or base to maintain a relatively constant pH.
For example, a buffer can be composed of dissolved acetic acid (a weak acid) and sodium acetate (a salt derived from that acid). Another example is a solution containing ammonia (a weak base) and ammonium chloride (a salt derived from that base).
Buffers play a crucial role in maintaining the pH stability of biological systems. They protect the molecules in solution from the effects of added acid or base, maintaining the physiological pH of biological fluids.