Which of the following would make the best buffer?
(a) a mixture of HCl and NaCl
(b) a mixture of NaOAc and NH3
(c) a mixture of HOAc and NH4Cl
(d) a mixture of NaOAc and NH4Cl
(e) a mixture of NH3 and NH4Cl
Chemistry · Sun Jul 10 2022
Answered on
The best buffer solution can be formed by a weak acid and its conjugate base, or a weak base and its conjugate acid.
In this case, we need to identify the weak acid and its conjugate base, or the weak base and its conjugate acid, among the given options.
(a) HCl is a strong acid, meaning it completely dissociates in solution and does not act as a buffer. NaCl is a salt, not an acid or base.
(b) NaOAc is the conjugate base of the weak acid HOAc (acetic acid), and NH3 is a weak base. This combination can form a buffer solution.
(c) HOAc is a weak acid and NH4Cl is its conjugate base. This combination can form a buffer solution.
(d) NaOAc is the conjugate base of HOAc, but NH4Cl is not the conjugate acid of NH3.
(e) NH3 is a weak base, but NH4Cl is not its conjugate acid.
Therefore, options (b) and (c) both have the potential to make the best buffer solutions.