Question

now we need to prepare a buffer that has a ph of 7.4. we need this specific ph to maintain our blood cells in culture. how should you prepare this buffer?
a) by mixing strong base and then adjusting the ph with strong acid
b) by mixing strong acid and then adjusting the ph with strong base
c) by mixing weak acid with its conjugate base and then adjusting the ph with strong base
d) by mixing weak base with its conjugate acid and then adjusting the ph with strong acid

Explanation:

Buffers are solutions that resist pH changes, made from a weak acid and its conjugate base, or a weak base and its conjugate acid. For a pH of 7.4 (slightly basic), starting with a weak acid-conjugate base pair and fine-tuning pH with a strong base is the correct approach. Strong acid/strong base mixtures do not form buffers, and a weak base-conjugate acid pair would start acidic, making strong acid adjustment incorrect for targeting 7.4.

Answer:

c) By mixing weak acid with its conjugate base and then adjusting the pH with strong base