, Farmic acid. HFor, has a Ka value equal to about 1.8 X 10 .A student is asked to prepare a buffer havingT of 3 55 from a solution of formic acid and a solution of sodium formate having the same molarity.Ham many mililiters of the NaFor solution should she add to 20. mL of the HFor solution to make thehemee0 buffer? (See discussion of buffers.)bovdoboeo 2015ibai e w ba aseloivberogndoloivwolleHqmL

Introduction: pH: pH is used to express the acidity of the solution. It is defined as the negative…

4. Formic acid, HFor, has a K, value equal to about 1.8 × 10¯*. A student is asked to prepare a buffer having l of 3 55 from a solution of formic acid and a solution of sodium formate having the same molarity. milliliters of the NaFor solution should she add to 20. mL of the HFor solution to make the How buffer? (See discussion of buffers.) many aM Hg ba

4. Formic acid, HFor, has a K, value equal to about 1.8 × 10¯*. A student is asked to prepare a buffer having l of 3 55 from a solution of formic acid and a solution of sodium formate having the same molarity. milliliters of the NaFor solution should she add to 20. mL of the HFor solution to make the How buffer? (See discussion of buffers.) many aM Hg ba

Chemistry: Principles and Reactions

8th Edition

ISBN:9781305079373

Author:William L. Masterton, Cecile N. Hurley

Publisher:William L. Masterton, Cecile N. Hurley

Chapter14: Equilibria In Acid-base Solutions

Section: Chapter Questions

Problem 14QAP: A buffer solution is prepared by adding 5.50 g of ammonium chloride and 0.0188 mol of ammonia to...

See similar textbooks

Similar questions

Sketch the titration curve for a weak acid titrated by a strong base. When performing calculations concerning weak acidstrong base titrations, the general two-slep procedure is to solve a stoichiometry problem first, then to solve an equilibrium problem to determine the pH. What reaction takes place in the stoichiometry part of the problem? What is assumed about this reaction? At the various points in your titration curve, list the major species present after the strong base (NaOH, for example) reacts to completion with the weak acid, HA. What equilibrium problem would you solve at the various points in your titration curve to calculate the pH? Why is pH 7.0 at the equivalence point of a weak acid-strong base titration? Does the pH at the halfway point to equivalence have to be less than 7.0? What does the pH at the halfway point equal? Compare and contrast the titration curves for a strong acidstrong base titration and a weak acidstrong base titration.
A buffer is prepared in which the ratio [ H2PO4 ]/[ HPO42 ]is 3.0. (a) What is the pH of this buffer? (b) Enough strong acid is added to convert 15% of HPO42- to H2PO4-. What is the pH of the resulting solution? (c) Enough strong base is added to make the pH 7.00. What is the ratio of [H2PO4-] to [HPO42-] at this point?
A buffer solution is prepared by adding 5.50 g of ammonium chloride and 0.0188 mol of ammonia to enough water to make 155 mL of solution. (a) What is the pH of the buffer? (b) If enough water is added to double the volume, what is the pH of the solution?
A friend asks the following: Consider a buffered solution made up of the weak acid HA and its salt NaA. If a strong base like NaOH is added, the HA reacts with the OH to form A. Thus the amount of acid (HA) is decreased, and the amount of base (A) is increased. Analogously, adding HCI to the buffered solution forms more of the acid (HA) by reacting with the base (A). Thus how can we claim that a buffered solution resists changes in the pH of the solution? How would you explain buffering to this friend?
The species called glacial acetic acid is 98% acetic acid by mass (d=1.0542g/mL). What volume of glacial acetic acid must be added to 100.0 mL of 1.25 M NaOH to give a buffer with a pH of 4.20?
A diprotic acid, H2B(MM=126g/moL), is determined to be a hydrate, H2B xH2O. A 10.00-g sample of this hydrate is dissolved in enough water to make 150.0 mL of solution. Twenty-five milliliters of this solution requires 48.5 mL of 0.425 M NaOH to reach the equivalence point. What is x?
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.
Define a buffer solution. What makes up a buffer solution? How do buffers absorb added H+ or OH with little pH change? Is it necessary that the concentrations of the weak acid and the weak base in a buffered solution be equal? Explain. What is the pH of a buffer when the weak acid and conjugate base concentrations are equal? A buffer generally contains a weak acid and its weak conjugate base, or a weak base and its weak conjugate acid, in water. You can solve for the pH by setting up the equilibrium problem using the K.a reaction of the weak acid or the Kb reaction of the conjugate base. Both reactions give the same answer for the pH of the solution. Explain. A third method that can be used to solve for the pH of a buffet solution is the HendersonHasselbalch equation. What is the HendersonHasselbalch equation? What assumptions are made when using this equation?
A buffer solution is prepared by adding 5.50 g of ammonium chloride and 0.0188 mol of ammonia to enough water to make 155 mL of solution. (a) What is the pH of the buffer? (b) If enough water is added to double the volume, what is the pH of the solution?
How much solid NaCH3CO23H2O must be added to 0300 L of a 0.50-M acetic acid solution to give a buffer with a pH of 5.00? (Him: Assume a negligible change in volume as the solid is added.)
Isocyanic acid (HNCO) can be prepared by heating sodium cyanate in the presence of solid oxalic acid according to the equation 2NaOCN(s)+H2C2O4(s)2HNCO(l)+Na2C2O4(s) Upon isolating pure HNCO(l), an aqueous solution of HNCO can be prepared by dissolving the liquid HNCO in water. What is the pH of a l00.-mL solution of HNCO prepared from the reaction of 10.0 g each of NaOCN and H2C2O4, assuming all of the HNCO produced is dissolved in solution? (Ka of HNCO = 1.2 l04.)
You have a solution of the weak acid HA and add some HCl to it. What are the major species in the solution? What do you need to know to calculate the pH of the solution, and how would you use this information? How does the pH of the solution of just the HA compare with that of the final mixture? Explain.