2. Joey was tasked to ensure that an enzyme responsible for keeping his species from extinction remains biologicallyactive. To do so, he needs to store it in a buffer solution with a pH of 10 00. Unfortunately, only three buffer systemsare available in their laboratoryBuffer System Weak Acid Component KConjugate Base SaltKYABenzoic acid, C,H,COOH 6.25 x 10 NaC,H,COOBoric acid, H;BO, 5.81 x 107 NaH BOHydrogen cyanide, HCN 620 X 10 10 NaCNMUHTWOA. In what buffer system (KYA, MUH, or TWO) will Joey store the enzyme?In your solution sheet, show calculations and briefly explain to support your answerB. Write the equilibrium reaction involved in the buffer system. Write your answer on your solution sheetC Calculate the amount (in mL) of the 1.75 M stock solution (pH 7.00) of the same buffer system needed to prepare250 mL of a 0.550 M buffer pH 7,00.

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2. Joey was tasked to ensure that an enzyme responsible for keeping his species from extinction remains biologically active. To do so, he needs to store it in a buffer solution with a pH of 10 00. Unfortunately, only three buffer systems are available in their laboratory Buffer System Weak Acid Component K Conjugate Base Salt KYA MUH TWO A. In what buffer system (KYA, MUH, or TWO) will Joey store the enzyme? In your solution sheet, show calculations and briefly explain to support your answer B. Write the equilibrium reaction involved in the buffer system. Write your answer on your solution sheet C Calculate the amount (in mL) of the 1.75 M stock solution (pH 7.00) of the same buffer system needed to prepare 250 mL of a 0.550 M buffer pH 7.00. Benzoic acid, C,H,COOH 6.25 x 10 NaC,H,COO Boric acid, H,BO, 5.81 x 107 NaH BO Hydrogen cyanide, HCN 620 X 10 10 NaCN

2. Joey was tasked to ensure that an enzyme responsible for keeping his species from extinction remains biologically active. To do so, he needs to store it in a buffer solution with a pH of 10 00. Unfortunately, only three buffer systems are available in their laboratory Buffer System Weak Acid Component K Conjugate Base Salt KYA MUH TWO A. In what buffer system (KYA, MUH, or TWO) will Joey store the enzyme? In your solution sheet, show calculations and briefly explain to support your answer B. Write the equilibrium reaction involved in the buffer system. Write your answer on your solution sheet C Calculate the amount (in mL) of the 1.75 M stock solution (pH 7.00) of the same buffer system needed to prepare 250 mL of a 0.550 M buffer pH 7.00. Benzoic acid, C,H,COOH 6.25 x 10 NaC,H,COO Boric acid, H,BO, 5.81 x 107 NaH BO Hydrogen cyanide, HCN 620 X 10 10 NaCN

Chemistry: An Atoms First Approach

2nd Edition

ISBN:9781305079243

Author:Steven S. Zumdahl, Susan A. Zumdahl

Publisher:Steven S. Zumdahl, Susan A. Zumdahl

Chapter14: Acid- Base Equilibria

Section: Chapter Questions

Problem 4RQ: A good buffer generally contains relatively equal concentrations of weak acid and conjugate base. If...

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Amino acids are an important group of compounds. At low pH, both the carboxylic acid group (CO2H) and the amine group (NHR) are protonated. However, as the pH of the solution increases (say, by adding base), the carboxylic acid proton is removed, usually at a pH between 2 and 3. In a middle range of pHs, therefore, the amine group is protonated, but the carboxylic acid group has lost the proton. (This is called a zwitterion.) At more basic pH values, the amine proton is dissociated. What is the pH of a 0.20 M solution of alanine hydrochloride, [NH3CHCH3CO2H]Cl?
When 40.00 mL of a weak monoprotic acid solution is titrated with 0.100-M NaOH, the equivalence point is reached when 35.00 mL base has been added. After 20.00 mL NaOH solution has been added, the titration mixture has a pH of 5.75. Calculate the ionization constant of the acid.
Given three acid-base indicatorsâ€”methyl orange (end point at pH 4), bromthymol blue (end point at pH 7), and phenolphthalein (end point at pH 9)â€”which would you select for the following acid-base titrations? (a) perchloric acid with an aqueous solution of ammonia (b) nitrous acid with lithium hydroxide (c) hydrobromic acid with strontium hydroxide (d) sodium fluoride with nitric acid
What is the pH of a buffer that is 0.175 M in a weak acid and 0.200 M in the acids conjugate base? The acids ionization constant is 5.7 104.
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Malonic acid (HO2CCH2CO2H) is a diprotic acid. In the titration of malonic acid w ith NaOH, stoichiometric points occur at pH = 3.9 and 8.8. A 25.00-mL sample of malonic acid of unknown concentration is titrated with 0.0984 M NaOH, requiring 31.50 mL of the NaOH solution to reach the phenolphthalein end point. Calculate the concentration of the initial malonic acid solution. (Sec Exercise 113.)
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What will be the pH of the buffer solution consisting of 94 mL butanoic acid (CH3CH2CH2COOH) 0.189 mol/L and 109 mL sodium butanoate (CH3CH2CH2COONa) 0.207 mol/L, if 10.9 mL KOH 0.5 mol/L is added?Give an answer to at least 3 decimal places.
10. One characteristic of blood that we rarely give a thought to is its pH. The pH of blood must be held remarkably constant, varying only by a few hundredths of a pH unit from 7.36 to 7.40. Blood pH is kept constant primarily through the buffering action of the bicarbonate ion, HCO3-, and dissolved carbon dioxide, commonly represented as H2CO3. The second ionization is negligible in blood so that H2CO3 can be treated as a monoprotic acid. A) If the Ka1 for H2CO3 is 4.2 * 10-7, what ratio of HCO3- to H2CO3 is necessary to produce a buffer of pH 7.40? B) What is the pH of a buffer that is 1.0 M NaHCO3 and 1.0 M H2CO3? C) If you have 1.00 L of the buffer described above (1.0 M NaHCO3 and 1.0 M H2CO3) and 10.0 mL of 0.100 M HCl is added to it, what is the new pH? D) Just to prove that the buffer helps minimize changes in pH, calculate the pH of a solution prepared by adding 10.0 mL of 0.1 M HCl to 1.00 L of pure water.
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