Identify a mixture from the following solution pairs where equal volumes of the two solutions, when mixed together, will lead to the formation of a buffer.

a) 0.13 M HCl with 0.15 M NaOH

b) 0.13 M H₂SO₄ with 0.13 M Na₂CO₃

c) 0.26 M HCN with 0.13 M KOH

d) 0.10 M NH₄Cl with 0.20 M HCl

The image below shows a buffer with equal amounts of weak acid, HA, and its conjugate base, A^–. If the column heights pertain to the amount of component present, select the image that shows the buffer after a strong acid is added.

For a buffer of pH 9.5, which of the following weak acid-conjugate base mixtures would you choose? Explain your choice.

a) CH₃COOH and NaCH₃COO

b) NH₄Cl and NH₃

c) HCOOH and NaHCOO

Identify whether the solution of the following compounds results in a buffer: 

250.0 mL 0.25 M CHCOOH and 105.0 mL of 0.050 M HCl