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

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

Explanation:

Hello,

In this case, considering that the buffer required a pH greater than 7 where the basic conditions are present, we need a weak base and its conjugate base in order to assure such pH greater than 7. Moreover, by using a strong acid, we can gently add it in order to decrease the pH up to 7.4 via a properly measured neutralization of the necessary moles of base up to a hydrogen concentration of 3.98x10⁻⁸ (pH). Therefore, answer is b) By mixing weak base with its conjugate acid and then adjusting the pH with strong  acid.

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the peripheral nervous system or pns contains the nerves, which leave the brain and the spinal cord and travel to certain areas of the body. the peripheral nervous system's main job is to send information gathered by the body's sensory receptors to the cns as quickly as possible.