Preparing Buffer Solutions: Calculating the Volume of Weak Base Needed Use the table of K values...
Preparing Buffer Solutions: Calculating the Volume of Weak Base Needed Use the table of K values given with this problem to choose the best weak base to start from for making a buffer that holds the pH of the solution at 5.00. Make your selection so that you maximize the capacity of the buffer. Assume that you want to make 700 mL of a buffer and you have already added enough of the conjugate acid salt to make the final...
Preparing Buffer Solutions: Calculating the Number of Grams of Conjugate Base Needed Use the table of K values given with this problem to choose the best weak acid to start from for making a buffer that holds the pH of the solution at 8.50. Make your selection so that you maximize the capacity of the buffer. Weak Acid K 1.8 X 10-5 6.5 X 10-5 1.5 X 10-5 You select a 800.0 ml volumetric flask to which you add 8.00...
Out of the following , which is the best acid/base to use to prepare a buffer with a PH of 4.00? a. sodium chloride b. sodium pyruvate c. aniline What ratio of masses of the weak acid/base and its conjugate should you use to make the buffer of the required PH? Use the sodium salt of the conjugate base if you chose a weak acid or the chloride salt of the conjugate acid if you chose a weak base.
For each of the weak acids listed below, consider how you would make a buffer solution where the weak acid has a concentration of 0.5 M at equilibrium. Determine what molarity for each potassium conjugate base salt would need to be added to make 500 mL of an effective buffer with a pH of 5.32. Which acid would make the best buffer at this pH? Which conjugate base salt would be the most economical (cheapest) out of the three choices? ...
a) Jim Bob analyses a buffer solution and finds it to contain in one liter: 0.220 moles of HA, and 0.430 moles of the conjugate base A-. If the Ka for the weak acid is 3.6 X 10-5. what is the pH of the buffer? b) Ephedrine (EP) is a weak acid, protonated amine which you take if you find yourself over weight, or falling asleep in class. You can buy the hydrochloride salt (HEP+)Cl (like the hydrochoride salt of...
The following shows a list of weak acids and bases with their Ka and Kb values. Substances Ka Substances Kb Cyanic acid (HCN) 4.9 x 10-10 Ammonia (NH3) 1.8 x 10-5 Nitrous acid (HNO2) 4.5 x 10-4 Aniline (C6H5NH2) 4.3 x 10-10 Hydrofluoric acid (HF) 6.8 x 10-4 Pyridine (C5H5N) 1.7 x 10-9 Acetic acid (CH3COOH) 1.8 x 10-5 Methylamine (CH3NH2) 4.4 x 10-4 If you want to make a pH 8.0 buffer solution, which of the following acids or...
Biochemistry problem! Next determine the recipe for making a buffer by mixing stock solutions of a buffer molecule (base form) and hydrochloric acid. The concentrations of the buffer (base) and HCl solutions are provided by the web page. Calculate the volume (in mL) needed to make a buffer with the same pH and concentration as in Question #1. Assume that water will be added to bring the volume up to the assigned total volume. Use the web page to check...
Strong base is dissolved in 635 mL of 0.600 M weak acid (K, = 3.03 x 10-5) to make a buffer with a pH of 4.08. Assume that the volume remains constant when the base is added. HA(aq) + OH(aq) →H,O(1) + A (aq) Calculate the pK, value of the acid, and determine the number of moles of acid initially present. pk = initial armount: initial amount: mol HA When the reaction is complete, what is the concentration ratio of...
You have 40.00 mL of a 0.300 M aqueous solution of the weak base C6H5NH2 (Kb = 4.00 x 10-10). This solution will be titrated with 0.300 M HCl. (a) How many mL of acid must be added to reach the equivalence point? (b) What is the pH of the solution before any acid is added? (c) What is the pH of the solution after 10.00 mL of acid has been added? (d) What is the pH of the solution...
3. Consider the following weak acids and their K, values, calculate the pK, for each acid. HC,H,O, - Acetic acid K. = 1.8 x 105 PK,= H,PO, - Phosphoric acid K = 7.1 x 10 PK, HCIO - Hypochlorous acid K = 3.5 x 10 pk = You want to prepare buffers at pH 2.8, 4.5 and 7.5. Which weak acid-conjugate base buffer system is the best choice for each pH from the acids listed? Write the reaction and indicate...