AASonic We have a buffer when we have a mixture of HA and A. Consider a buffer with equal amounts of Acetic Acid (pKa 4.76) and Acetate (For example, 25.0 mls of 0.100 M HAc and 25.0 mls of 0.100 M Ac-). What is the pH of this buffer? Let's calculate the pH change upon addition of 5.00 mls of 0.100 M HCl. Uslng our reaction from part 3, fill in the initial moles of each species, then use stoichiometry to calculate change and final. 5) НА H + A> Initial Change Final Calculate the pH An alternate way to make a buffer is to mix a strong base with a weak acid. Let's look at how 6) this works. Consider a solution of 25.0 mls of 0.200 M Acetic Acid. Add to it 25.0 mLs of 0.100 M NaOH. Using our reaction from part 2, fill in initial moles of each species. Use stoichiometry to calculate change/final. Compare the final moles and concentrations to the initial buffer in part 5 A +H20 ОН + HA Initial Change Final Calculate the pH and the % of dissociation for your assigned solution(s) of acetic acid and add point(s) to table on board and to grapbs (on back). initial [HA] [H*] % Dissociation 1.00 M 0.75 M 0.50 M 0.25 M .00131 2.88 1.3 0.10 M 0.050 M 0.010 M

AASonic We have a buffer when we have a mixture of HA and A. Consider a buffer with equal amounts of Acetic Acid (pKa 4.76) and Acetate (For example, 25.0 mls of 0.100 M HAc and 25.0 mls of 0.100 M Ac-). What is the pH of this buffer? Let's calculate the pH change upon addition of 5.00 mls of 0.100 M HCl. Uslng our reaction from part 3, fill in the initial moles of each species, then use stoichiometry to calculate change and final. 5) НА H + A> Initial Change Final Calculate the pH An alternate way to make a buffer is to mix a strong base with a weak acid. Let's look at how 6) this works. Consider a solution of 25.0 mls of 0.200 M Acetic Acid. Add to it 25.0 mLs of 0.100 M NaOH. Using our reaction from part 2, fill in initial moles of each species. Use stoichiometry to calculate change/final. Compare the final moles and concentrations to the initial buffer in part 5 A +H20 ОН + HA Initial Change Final Calculate the pH and the % of dissociation for your assigned solution(s) of acetic acid and add point(s) to table on board and to grapbs (on back). initial [HA] [H*] % Dissociation 1.00 M 0.75 M 0.50 M 0.25 M .00131 2.88 1.3 0.10 M 0.050 M 0.010 M

Appl Of Ms Excel In Analytical Chemistry

2nd Edition

ISBN:9781285686691

Author:Crouch

Publisher:Crouch

Chapter7: Neutralization Titrations And Graphical Representations

Section: Chapter Questions

Problem 1P

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Similar questions

What mass of NH4Cl must be added to 0.750 L of a 0.100-M solution of NH3 to give a buffer solution with a pH of 9.26? (Him: Assume a negligible change in volume as the solid is added.)
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 10.00-g sample of the ionic compound NaA, where A is the anion of a weak acid, was dissolved in enough water to make 100.0 mL of solution and was then titrated with 0.100 M HCl. After 500.0 mL HCl was added, the pH was 5.00. The experimenter found that 1.00 L of 0.100 M HCl was required to reach the stoichiometric point of the titration. a. What is the molar mass of NaA? b. Calculate the pH of the solution at the stoichiometric point of the 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?
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.
A buffer is prepared by dissolving 0.062 mol of sodium fluoride in 127 mL of 0.0399 M hydrofluoric acid. Assume no volume change after NaF is added. Calculate the pH of this buffer.
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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?
A buffer solution is 0.366 M in HF and 0.372 M in KF . If Ka for HF is 7.2×10-4 , what is the pH of this buffer solution? --- A buffer solution is 0.485 M in NAHS and 0.336 M in . If ka1 for H2S is , what is the pH of this buffer solution? pH =
Two buffers are prepared by adding an equal numberof moles of formic acid (HCOOH) and sodium formate(HCOONa) to enough water to make 1.00 L of solution.Buffer A is prepared using 1.00 mol each of formic acid andsodium formate. Buffer B is prepared by using 0.010 mol ofeach. (a) Calculate the pH of each buffer. (b) Which bufferwill have the greater buffer capacity? (c) Calculate thechange in pH for each buffer upon the addition of 1.0 mLof 1.00 M HCl. (d) Calculate the change in pH for each bufferupon the addition of 10 mL of 1.00 M HCl.
What is [H3O+] and the pH of a solution of 0.052 M HNO2 and 0.041 M KNO2? Hint: This is a buffer.
1. What will be the pH when 50.0 ml of 2.00M carbonic acid is mixed 20.0 ml of 3.00 M sodium bicarbonate? The Ka of carbonic is 4.30 x 10-7. - For the buffer system in Problem no. 1, what will be the pH when (a) 15.0 ml of 0.500 M HCl and (b) when 15.0 ml of 0.750 M NaOH is added to the buffer?