A buffer is prepared using acetic acid, CH3COOH, (a weak acid, pK = 4.75) and sodium acetate, CH,COONA (which provides acetate ions, the conjugate base), according to the following proportions: Volume of CH3COOH(aq): 109.0 mL Concentration of CH3COOH(aq): 1.281 M Volume of CH3COONA(aq): 142.0 mL Concentration of CH3COONA(ag): 1.043 M A 50 mL sample of this original buffer is transferred to a clean and dry beaker, to this solution 150 mL of deionized water is added. Calculate the pH of this new, diluted buffer solution. O 4.75 4.72 4.78 4.84 O 4.66

A buffer is prepared using acetic acid, CH3COOH, (a weak acid, pK = 4.75) and sodium acetate, CH,COONA (which provides acetate ions, the conjugate base), according to the following proportions: Volume of CH3COOH(aq): 109.0 mL Concentration of CH3COOH(aq): 1.281 M Volume of CH3COONA(aq): 142.0 mL Concentration of CH3COONA(ag): 1.043 M A 50 mL sample of this original buffer is transferred to a clean and dry beaker, to this solution 150 mL of deionized water is added. Calculate the pH of this new, diluted buffer solution. O 4.75 4.72 4.78 4.84 O 4.66

Chemistry

10th Edition

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Chapter1: Chemical Foundations

Section: Chapter Questions

Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...

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43. A buffer is prepared using acetic acid, CH3COOH, (a weak acid, pKa = 4.75) and sodium acetate, CH3COONa (which provides acetate ions, the conjugate base), according to the following proportions: Volume of CH3COOH(aq): 125.0 mL Concentration of CH3COOH(aq): 1.263 M Volume of CH3COONa(aq): 106.0 mL Concentration of CH3COONa(aq): 1.279 M Determine the volume of 6.00 M HCl required to change the pH of this buffer by one pH unit. 18.15 mL 36.30 mL 21.87 mL 19.30 mL 43.73 mL
What is the general equation given when examining a titration? O A (aq) + H20 (1) = HA + OH (aq) (aq) H*e (aq) + ОН (aq) + OH' = H2O (1) О НА (aq) + H20 () =A (aq) + H3O*(aq) O HA (ag) + NaOH (ag) = NaA (aq) + H2O (1)
A phosphate buffer contains KH2PO4 and K2HPO4. What is the net ionic equation for the buffering reaction that occurs when some HCl is added to the buffer solution? (A) H2PO4–(aq) + Cl–(aq) --> HPO42–(aq) + HCl(aq); (B) H2PO4–(aq) + H3O+(aq) --> H3PO4(aq) + H2O(aq); (C) HPO42–(aq) + Cl–(aq) --> PO43–(aq) + HCl(aq); (D) HPO42–(aq) + H3O+(aq) --> H2PO4–(aq) + H2O(aq);
The organic bases cocaine pKb = 8.412 and codeine pKb = 7.952 react with hydrochloric acid to form salts (similar to the formation of NH4Cl by the reaction of NH3 and HCl). If solutions of the following salts have the same molarity, which solution would have the higher pH: cocaine hydrochloride, C H O NH+Cl-, or codeine hydrochloride, C H ClO NH+Cl-? Show your step by step solution and explanation of your solution.
The organic bases cocaine pKb = 8.412 and codeine pKb = 7.952 react with hydrochloric acid to form salts (similar to the formation of NH4Cl by the reaction of NH3 and HCl). If solutions of the following salts have the same molarity, which solution would have the higher pH: cocaine hydrochloride, C H O NH+Cl-, or codeine hydrochloride, C H ClO NH+Cl-? Show your step by step solution and explanation of your solution. *either write pka=14-pkb, and explain why trend of pH is same as pka or from pKb explain how to get pH of conjugate acid from pOH trend of Kb of base.
A 0.018 M solution of salicylic acid, HOC6H4CO2H, has the same pH as 0.0038 M HNO3solution. (a) Write an equation for the ionization of salicylic acid in aqueous solution. (Assume only the –CO2H portion of the molecule ionizes.) (b) What is the pH of solution containing 0.018 M salicylic acid? (c) Calculate the Ka of salicylic acid.
ssume you dissolve 0.235 g of the weak acid benzoic acid, C6H5CO2H, in enough water to make 7.00 ✕ 102 mL of solution and then titrate the solution with 0.153 M NaOH. C6H5CO2H(aq) + OH-(aq) C6H5CO2-(aq) + H2O(ℓ) What are the concentrations of the following ions at the equivalence point? Na+, H3O+, OH-C6H5CO2- M Na+ M H3O+ M OH- M C6H5CO2-
Determine the pH at the point in the titration of 40.0 mL of 0.200 M H₂NNH₂ with 0.100 M HNO₃ after 100.0 mL of the strong acid has been added. The value of Kb for H₂NNH₂ is 3.0 × 10⁻⁶. Use the table below to determine the moles of reactant and product after after the reaction of the acid and base. H2NNH2(aq) + H+ (aq) --> H2NNH3+(aq) Before (mol) Change (mol) After (mol) ** solve for pH and fill the table in
Consider a buffer solution that consists of two separate components: the weak acid, CH3COOH(aq), and its conjugate base, CH3COO¯ (aq) (added as NaCH3COO). Which component will react with H+(aq) from a strong acid? Write the net ionic equation for the reaction that occurs when H+(aq) is added to the buffered solution. Which component will react with OH-(aq) from a strong base? Write the net ionic equation for the reaction that occurs when OH-(aq) is added to the buffered solution.
(a) Using the expression Ka=[H+][A−]/[HA], explain how to determine which solution has the lower pH, 0.10MHF(aq) or 0.10MHC2H3O2(aq). Do not perform any numerical calculations. (b) Which solution has a higher percent ionization of the acid, a 0.10M solution of HC2H3O2(aq) or a 0.010M solution of HC2H3O2(aq) ? Justify your answer including the calculation of percent ionization for each solution.
A chemist takes 8.579 mL of liquid acetic acid, CH;COOH (molar mass: 60.052 g/mol) with 1.05 g/ml density and mix it with 12.305 g of solid sodium acetate, CH,COONA (molar mass: 82.0343g/mol) and prepare an aqueous solution of 1.0 L by adding required amount of water. (Acidity constant of CH;COOH is 1.8x10-5) a) What is the pH of such solution?
6. a) What is the pH of pure water at 35.0 °C? At this temperature Kw = 2.042 x 10-14. b) Based on the information in part a) above, is the self-ionization of water an endothermic or exothermic process? Explain why. c) The net ionic equation for the reaction of a strong acid with a strong base is: H3O*(aq) + OH(aq) 2 H-ОФ What is the equilibrium constant for this reaction at 35.0 °C?