The amino acid glycine has been used as a buffer for a number of biochemical experiments. Glycine contains two ionizable groups, one with a pKa of 2.34, and the other with a pKa of 9.60. Glycine would be an effective buffer at which one of the following pH values? A. 4.0 B. 6.0 C. 8.0 D. 9.0 E. 11.0

A 25.0 mL sample of a 0.2500 M  solution of aqueous trimethylamine is titrated with a 0.3125 M  solution of HCl. Calculate the pH of the solution after 10.0, 20.0, and 30.0 mL of acid have been added; pKb of (CH3)3N = 4.19 at 25°C.   pH after 10.0 mL of acid have been added =   pH after 20.0 mL of acid have been added =    pH after 30.0 mL of acid have been added =

You wish to prepare an HC2H3O2 buffer with a pH of 5.14. If the pKa of is 4.74, what ratio of C2H3O2⁻/HC2H3O2 must you use?

Which of the following buffer systems would be the best choice to create a buffer with pH = 9.05? HF/KF HNO2/KNO2 NH3/NH4Cl HCIO/KCIO Submit Previous Answers Correct The best buffer will be the one whose weak acid component has a pK₂ closest to the desired pH of the buffer. Since the pK₂ of NH4+ is 9.25, and the desired buffer pH is 9.05, the best choice for the buffer is NH3/NH4Cl. Part B For the best system, calculate the ratio of the masses of the buffer components required to make the buffer. Express your answer using two significant figures. VT ΑΣΦ m (NH3) m (NH4Cl) Submit Poquest Answer ?

Given a 0.300 M solution of anserine at its isoelectric point and ready access to 0.100 M HCl, 0.100 M NaOH and distilled water, describe the preparation of 1 L of 0.0300 M anserine buffered solution, pH 7.20. Volume of stock solution needed =  mL Volume of HCl needed to adjust the imidazole group =  mL Volume of HCl needed to titrate the amino group =  mL Total HCl needed =  mL pi=8.27

Consider the list of acids and their pKa values to the right. What two compounds would be best to use in preparing a pH 9.0 buffer solution? Justify your answer. Assume you have the acids and the sodium salts of their conjugate bases available to you.

1. When making a buffer of pH = 10, weak molecules with the following Ka values are available.  Which would be the best to use? 2.  A weakly acidic drug with pKa of 4.4 will exert its action on the stomach where the pH is 1.4.  Which of the following statements is CORRECT? 3. What happens to a buffer composed of 0.5M 10 mL acetate and 0.5M 15 mL acetic acid when 1 mL of 0.2M sodium hydroxide is added? The Ka of acetic acid is 1.8 x 10 exp negative 5.

Chemistry Consider a buffered solution with a pH of 11 that contains tyrosine as a free amino acid. What is the net charge carried by the predominant form of tyrosine in this solution? Consider a buffered solution with a pH of 9.5 that contains lysine as a free amino acid. What is the net charge carried by the predominant form of lysine in this solution?

A biochemist is trying to prepare 800.0mL of buffer using KH2PO4 and K2HPO4 combination, pKa for these two salts are 6.86 and 12.4 respectively. If the pH of the buffer that the biochemist is trying to prepare is 7.0 and the total concentration of the phosphate is 0.200M. Determine the mass in grams of KH2PO4 and K2HPO4 that is required to make 800.0mL

A chemist titrates 50.0 mL of a 0.4629 Methylamine (C₂H-NH₂) solution with 0.1652 MHNO3 solution at 25 °C. Calculate the pH at equivalence. The pK, of ethylamine is 3.19. Round your answer to 2 decimal places. Note for advanced students: you may assume the total volume of the solution equals the initial volume plus the volume of HNO3 solution added. pH = 0 X Ś