Question

Which of the following combinations can be used to make a buffer? (Assume equal

volumes are used.)
A) 0.20 M NH, and 0.20 M HCI
B) 0.20 M NH, and 0.10 M NH CI
C) 0.20 M NH, and 0.10 M HF
D) 0.10 M NH CI and 0.10 M NaF

Answer 1

A buffer solution can be made using 0.20 M NH4Cl and 0.20 M NH3, or 0.10 M NH4Cl and 0.10 M NaF.

Step-by-step explanation:

A buffer solution is made up of a weak acid and its conjugate base or a weak base and its conjugate acid. The combinations that can be used to make a buffer solution are:

1. 0.20 M NH4Cl and 0.20 M NH3
2. 0.20 M NH4Cl and 0.10 M NaF

Option A (0.20 M NH4Cl and 0.20 M HCl) is not a buffer solution because HCl is not a weak acid.

Option C (0.20 M NH4Cl and 0.10 M HF) is not a buffer solution because HF is not a weak acid.

Option D (0.10 M NH4Cl and 0.10 M NaF) is a buffer solution because NH4Cl is the weak acid NH4^+ and NaF is the conjugate base F^-.