Question

Which of the following acid/base combinations could be used to prepare a buffer solution? Select all that apply. .

a. HNO₂, and NaNO₃,
b. HCN and KCN
c. HNO₂, and NaNO₂,
d. KH₂PO₄, and K₂HPO₄,
e. H₂O and Ca(OH)₂

Answer 1

The acid/base combinations that can be used to prepare a buffer solution are HNO₂ and NaNO₂, and HCN and KCN, and KH₂PO₄ and K₂HPO₄.

Step-by-step explanation:

A buffer solution is a solution that is resistant to changes in pH when small amounts of acid or base are added. In order to prepare a buffer solution, you need a weak acid and its conjugate base or a weak base and its conjugate acid.

From the given options, the acid/base combinations that can be used to prepare a buffer solution are:

• HNO₂ (weak acid) and NaNO₂ (conjugate base)
• HNO₂ (weak acid) and NaNO₃ (not correct because NaNO₃ is the salt of a strong acid and strong base)
• HCN (weak acid) and KCN (conjugate base)
• KH₂PO₄ (weak acid) and K₂HPO₄ (conjugate base)