Describe the pH changes that occur during the titration of a weak base by a strong acid. What is meant by the term equivalence point?

1) Write the equilibrium constant expression for the dissociation of acetic acid 2) Vinegar sold commercially is typically 0.8−1.0 M acetic acid. A 1.00 M solution of acetic acid is measured by its pH to have an equilibrium concentration of 4.19×10−3 M for both acetate ions and hydronium ions at room temperature. Assuming [HOAc]0 = 1.00 M, what is the equilibrium concentration of undissociated acetic acid [HOAc]eq to the correct number of significant figures? 3) What is the value of the equilibrium constant Keq for the dissociation according to the concentrations from number 2?

You have a 18 mL sample of acetylcholine (a neurotransmitter) with an unknown concentration and a pH of 8.35. 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. At the end of the incubation period, you measure the pH again and find that it has decreased to 6.03. Assuming there was no buffer in the assay mixture, determine the number of nanomoles of acetylcholine in the original 18 mL sample.

You have a 12 mL sample of acetylcholine (a neurotransmitter) with an unknown concentration and a pH of 8.14. 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. At the end of the incubation period, you measure the pH again and find that it has decreased to 6.55. Assuming there was no buffer in the assay mixture, determine the number of nanomoles of acetylcholine in the original 12 mL sample. Acetycholine in original sample:________ nmol

You have a 18 mL sample of acetylcholine (a neurotransmitter) with an unknown concentration and a pH of 7.82. 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. At the end of the incubation period, you measure the pH again and find that it has decreased to 5.66. Assuming there was no buffer in the assay mixture, determine the number of nanomoles of acetylcholine in the original 18 mL sample. Tip: your answer should have two significant digits! Only the mantissa (the digits to the right of the decimal) are significant when you raise a decimal number to a power. CH,—C−O−CH,—CH,—*N—CH, Acetylcholine CH 3 acetycholine in original sample: CH3 H₂O CH3 HO–CH,—CH,—*N–CH, + CH, Choline CH3 CH, T Acetate O + H+ nmol

A buffer system is prepared by combining 0.603 moles of ammonium chloride (NH4CI) and 0.713 moles of ammonia (NH3). What will the solution pH be if 0.239 moles of the nitric acid (HNO3) is added to the solution. Nitric acid is a strong acid. The K₁ of ammonia is 1.8 x 10-5. (Two decimal places)

A 0.1724-g sample of an unknown monoprotic acid was dissolved in 26.9 mL of water and titrated with 0.0623 M NaOH solution. The volume of base required to bring the solution to the equivalence point was 19.8 mL. (a) Calculate the molar mass of the acid. (b) After 11.5 mL of base had been added during the titration, the pH was determined to be 5.66. What is the Ka of the unknown acid?

Determine the concentration of C₆H₅NH₃⁺ in a buffer solution by constructing an ICE table, writing the equilibrium constant expression, and using this information to determine the concentration of C₆H₅NH₃⁺. Complete Parts 1-3 before submitting your answer. A buffer solution contains dissolved C6H5NH2 and C6H5NH3Cl. The initial concentration of C6H5NH2 is 0.50 M and the ph of the buffer is 4.20. The kb for C6H5NH2 is 3.8 * 10^-10.

A 0.1276 g sample of an unknown monoprotic acid was dissolved in 25.0 mL of water and titrated with 0.0633 M NaOH solution. The volume of base required to bring the solution to the equivalence point was 18.4 mL. (a) Calculate the molar mass of the acid. (b) After 10.0 mL of base had been added during the titration, the pH was determined to be 5.87. What is the Ka of the unknown acid? *only need help with b

You have a 11 mL sample of acetylcholine (a neurotransmitter) with an unknown concentration and a pH of 8.22. 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. At the end of the incubation period, you measure the pH again and find that it has decreased to 6.62. Assuming there was no buffer in the assay mixture, determine the number of nanomoles of acetylcholine in the original 11 mL sample. CH,—C−O−CH,—CH,—*N-CH, Acetylcholine CH3 acetycholine in original sample: I CH₂ H₂O CH₂ HO–CH,—CH,—*N–CH, + CH,-C−O + H* CH₂-8-0 Choline | CH3 Acetate nmol