The concentration of acetylcholine (a neurotransmitter) in a sample can be determined from the pH changes that accompany its hydrolysis. When the sample is incubated with the enzyme...

The concentration of
acetylcholine (a neurotransmitter) in a sample can be determined from the pH changes that
accompany its hydrolysis. When the sample is incubated with the enzyme
acetylcholinesterase, acetylcholine is converted to choline and acetic acid, which
dissociates to yield acetate and a hydrogen ion:

In a typical analysis, 15 mL of an aqueous solution containing an unknown amount of
acetylcholine had a pH of 7.65. When incubated with acetylcholinesterase, the pH of the
solution decreased to 6.87. Assuming there was no buffer in the assay mixture, determine
the number of moles of acetylcholine in the 15 mL sample.

Extracted text: CH3 H20 CH3-Č-0-CH2-CH2N-CH3 ČH3 Acetylcholine CH3 HO-CH2-CH2N-CH3 + CH3-ç-o-+ H+ ČH3 Choline Acetate