9. Measurement of Acetylcholine Levels by pH Changes You have a 15 mL sample of acetylcholine (a neurotransmitter) with an unknown concentration and a pH of 7.65. You incubate this sample with the enzyme acetylcholinesterase to convert all of the acetylcholine to choline and acetic acid. The acetic acid dissociates to yield acetate and hydrogen ions. 010 CH3 H₂O CH3-C-O-CH2-CH2-N-CH3 CH3 Acetylcholine CH3 HO-CH2-CH2-N-CH3 + CH3-C-0¯ + H+ CH3 Choline Acetate At the end of the incubation period, you measure the pH again and find that it has decreased to 6.87. Assuming there was no buffer in the assay mixture, determine the number of nanomoles of acetylcholine in the original 15 mL sample.

The average normal concentration of Ca2+ in urine is 5.33 g/L. Calculate the concentration of oxalate needed to precipitate calcium oxalate to initiate formation of a kidney stone. Ksp of calcium oxalate = 2.3 × 10−9. Calculate the minimum phosphate concentration that would precipitate a calcium phosphate kidney stone. Ksp of calcium phosphate = 2.0 × 10−29.

9. Measurement of Acetylcholine Levels by pH Changes You have a 15 mL sample of acetylcholine (a neurotransmitter) with an unknown concentration and a pH of 7.65. You incubate this sample with the enzyme acetylcholinesterase to convert all of the acetylcholine to choline and acetic acid. The acetic acid dissociates to yield acetate and hydrogen ions. O CH3 CH3-C-O-CH2-CH2-N–CH3 Acetylcholine CH3 H₂O CH3 HỌCH, CH, N– CH3 + CH3-CHO TH 11 CH3 Choline Acetate T 4 At the end of the incubation period, you measure the pH again and find that it has decreased to 6.87. Assuming there was no buffer in the assay mixture, determine the number of nanomoles of acetylcholine in the original 15 mL sample.

Write the equilibrium for Congo red, showing the color changes that accompany it. Include both of the changes found in both acidic and basic conditions. In basic conditions, the formula for Congo red is Na2C32H22N6Na2O6S2. In acidic conditons, the formula for Congo red is NaC32H23N6Na2O6S2.

21- The mass-action effect is a shift in the position of an equilibrium caused by adding one of the reactants or products to a system. O True O False 20- Buffer solution is a mixture of a weak acid and it's salt. or weak base and it's salt. the pH of buffer resists change upon adding small amount of strong acid or base or when it dilute. O True O False I 22- Equilibrium-constant are algebraic equations that describe the concentration relationships among reactants and products at equilibrium O True O False ترك السؤال ترك السؤال ارسال الاجابة ارسال الاجابة

Upon adding 0.75 g sulfamic acid to 0.85 M solution of NaNO,, you notice that there is violent bubbling, a release of heat, and the formation of an orange-brown gas. Your lab partner isolates the gas in a stoppered test tube. The equilibrium for the orange-brown gas generated from the experiment is shown below. 2NO2) N20Alg) AHxn <0 (orange-brown) (colorless) What would you observe upon placing the test tube with the colored gas in an ice bath? O The orange-brown color would become even more intense. O The gas would become a brown liquid, and then solidify. O The test tube would become very hot. O The color would gradually fade. It is impossible to tell with the information provided

The following compounds are of interest in pharmaceutical chemistry, since they are part of the synthesis of active drug ingredients. Write the chemical reaction to synthesize them, and indicate which reaction it belongs (Note: Remember that there may be more than one synthesis route therefore there may be different answers) 1 Ph

Write the Ksp expression for the sparingly soluble compound silver carbonate, Ag2CO3. Ksp =       If either the numerator or denominator is 1, please enter 1.

What does the color change of phenolphthalein, from clear to pink, in an acid-base titration indicate? O The pH of the solution has decreased. O The pH of the solution has increased. O The green absorbance has decreased to zero. O The solution has become more acidic. O The pOH of the solution has increased.

What buffers are in blood plasma and how are acidosis and alkalosis involved in the changes of pH balance?