Question 19

Buffers are solutions that resist changes in pH.

Buffers are defined as solutions that maintain a relatively constant pH level when small amounts of acid or base are added. This property is essential in various biological and chemical processes where pH stability is crucial.

A) Proteins

While some proteins can act as buffers due to their ability to accept or donate protons, they are not classified as buffers in a general sense. Buffers specifically refer to solutions that can resist changes in pH, making this option incorrect.

B) Solutions that resist changes in pH

This option accurately describes buffers, which are solutions that can maintain their pH level despite the addition of acids or bases. The ability to resist pH changes is the defining characteristic of a buffer, making this the correct answer.

C) Catalysts in a reaction

Catalysts speed up chemical reactions without being consumed in the process, but they do not have the ability to resist changes in pH. Therefore, this option does not relate to the definition of buffers and is incorrect.

D) Inhibitors in a reaction

Inhibitors are substances that slow down or prevent chemical reactions but do not relate to the concept of pH stability. Since buffers are specifically solutions that maintain pH, this option is also incorrect.

Conclusion

Buffers play a crucial role in maintaining pH stability in various environments, which is why option B is definitively correct. Other options fail to describe the essential characteristics of buffers, focusing instead on unrelated concepts such as proteins, catalysts, and inhibitors.