Which of the following solutions will be buffers? Explain your answer in each case. a) 0.10 M KCN mixed with 0.10 M HCN b) 1.0 M NaOH mixed with 1.0 M NaCl.
a. 0.10 M KCN mixed with 0.10 M HCN: This solution will act as a buffer because it contains a weak acid (HCN) and its conjugate base (C--N). The presence of both a weak acid and its conjugate base allows the solution to resist changes in pH when small amounts of acid or base are added.

b. 1.0 M NaOH mixed with 1.0 M NaCl: This solution will not act as a buffer because it does not contain a weak acid and its conjugate base. Instead, it contains a strong base (NaOH) and its salt (NaCl). A buffer solution requires the presence of a weak acid and its conjugate base in order to resist changes in pH.