QUESTION TO ANSWER : * A mixture of 0.20M acetic acid and 0.30M sodium acetate is given. Calculate the pH of the medium if the pKa of the acetic acid is 4.76. Show your complete solution.Note : SEE EXAMPLE IN THE IMAGE 2. What is the ratio of the concentration of acetic acid and acetate ions requiredto prepare a buffer with pH 5.20. The pka of acetic acid is 4.76.Solution:You cannot directly apply the Henderson - Hasselbalch equation because it is anindirect question. First, you need to rearrange the equation accordingly.A.) Following components are given in the equation:pH of the buffer = 5.20pka of acetic acid = 4.76B.) Formula:[Proton Acceptor]pH = pka + log[Proton Donor]C.) Rearrange the Components:[Proton Acceptor]log[Proton Donor]= pH - pKa[Proton Acceptor]log[Proton Donor]= 5.20 – 4.76[Proton Acceptor]log[Proton Donor]= 0.44[Proton Acceptor]log= antilog of 0.44 = 2.75[Proton Donor]Answer: The ratio of acetate to acetic acid required to get pH of 5.20 is 2.75. Sample Problems1. The pH of the given solution of lactic acid and lactate is 4.30. Calculate the pkaof lactic acid, when the concentration of lactic acid and lactate are 0.020M and0.073M, respectively.Solution:A.) Following components are given in the equation:pH of the medium = 4.30Concentration of lactate ion (proton acceptor) = 0.073MConcentration of lactic acid (proton donor) = 0.020MB.) Formula:[Proton Acceptor][Proton Donor]pHpKa + log%3DWe need to calculate the pKa of lactic acid. So, take out the pKa to the left side andthe equation now becomes:[Proton Acceptor]log[Proton Donor]pKapH%3DC.) Substitute the given values in the new equation:0.073pKa =4.30 – log0.0204.30 – log 3.65log 3.65 is 0.56pKa =4.30 – 0.563.74Answer: the pKa of the given solution is 3.74C.) Substitute the given values in the new equation:0.073pKa4.30 – log%3D0.0204.30 – log 3.65%3Dlog 3.65 is 0.56pKa =4.30 – 0.563.74%3DAnswer: the pKa of the given solution is 3.74

A. Following components are given in the equation: Concentration of acetic acid (proton donor) =…

Answered: A mixture of 0.20M acetic acid and…

A mixture of 0.20M acetic acid and 0.30M sodium acetate is given. Calculate the pH of the medium if the pKa of the acetic acid is 4.76.

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter14: Principles Of Neutralization Titrations

Section: Chapter Questions

Problem 14.32QAP

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