In making buffer 4, dissolve 5.04g disodium hydrogen phosphate (base) and 3.01g of potassium dihydrogen phosphate (acid) in sufficient water to produce 1000mL. Adjust the pH with glacial acetic acid. At what concentration was both base and acid prepared?

2. If an acetic acid/sodium acetate buffer solution is prepared from 100. mL of 0.10 M acetic acid what volume of 0.10 M sodium acetate must be added to have a pH of 4.00? 100. mL 50. mL 36 mL 18 mL

2. At 25°C, a 1-L buffer solution is prepared by mixing acetic acid and sodium acetate. A) If the solution is to be buffered at pH= 5, what should be the molar ratio of sodium acetate to acetic acid? B) If the buffer is found to be 1.55M in acetic acid and 1.70M in sodium acetate, what will be the pH of the solution?

4) a) Determine the mass (in grams) of sodium formate that must be added to 1.00 Lof 0.180 M formic acid to prepare a buffer with a pH = 3.50. Assume there is no change in volume upon addition of the sodium formate. b) Write the predominant chemical reaction that occurs when 0.050 mol of HCIO, is added to 1.00 L of the buffer prepared in part a and calculate the pH of the solution.

The Ka of bromoacetic acid is 2.00 ×10–3.  What masses of bromoacetic acid (CH2BrCOOH) and sodium bromoacetate (CH2BrCOONa) are needed to prepare 1.00 L of pH = 1.700 buffer if the total concentration of the two components is 0.200 M?

A mixture of sodium carbonate (Na2CO3) and sodium bicarbonate (NaHCO3) is dissolved in water and titrated with 0.100 M HCl. Methyl orange and phenolphthalein are employed for the titration. Methyl orange changes color from red to yellow between pH 3.1 and 4.4 with increasing pH, while phenolphthalein changes from colorless to red between pH 8.0 and 9.6 with increasing pH. 12.00 mL of HCl is required to reach the phenolphthalein end point in the titration of the mixture. The titration of a second aliquot of the mixture requires 34.00 mL of titrant to reach the methyl orange end point. (i) What is the major species present in the solution at each end point?(ii) How many millimoles of carbonate and bicarbonate are in the sample?

At 25oC, a 1-L buffer solution is prepared by mixing acetic acid and sodium acetate.A) If the solution is to be buffered at pH = 5, what should be the molar ratio of sodium acetate to acetic acid?B) If the buffer is found to be 1.50M in acetic acid and 1.75M in sodium acetate, what will be the pH of the solution?C) If 0.05 mol of NaOH was added to the solution in B, what will be the pH of the solution?D) If the pH of the solution in B is 4.55, how many moles of HCl was added to the solution?

How many grams of solid potassium butanoate (CH,CH,CH;CO,K, 126.196 g/mol ) would have to be added to 325 mL ofa 0.609 M butanoic acid (CH;CH,CH-CO,H) solution to achieve a buffer of pH 4.1752 Assume there is no volume change upon adding the salt. (K for CH;CH3CH;CO,H=152 x10 )

11) Choose the acid below that would make the most effective buffer for a solution to maintain a pH of 5.00 (aq., 25 °C), given a 0.500 M concentration of it and its conjugate salt. a) propionic acid, Ka = 1.34 x 10 1.90 x 10 b) HN, Ka = %3D c) butanoic acid, Ka = 1.52 x 10° d) NH4CI, Ka = 5.56 x 101" e) benzoic acid, Ka = 6.30 x 10

Be sure to answer all parts. Tris [tris(hydroxymethyl)aminomethane] is a common buffer for studying biological systems. (K = 5.01 × 10 and pK = 8.3) (a) Calculate the pH of the Tris buffer after mixing 11.0 mL of 0.20 M HCl solution with 25.0 mL of 0.10 M Tris. (b) This buffer was used to study an enzyme-catalyzed reaction. As a result of the reaction, 0.00019 mol of H* was produced. What is the pH of the buffer at the end of the reaction? (c) What would be the final pH if no buffer were present?