Weak Acid Titration
- Page ID
- 282816
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)Titration of Weak Acid with Strong Base
Consider the titration of 50.00 mL of 0.02000 M MES with 0.1000 M NaOH. MES is an abbreviation for 2-(N-morpholino)ethanesulfonic acid, which is a weak acid with pKa = 6.27.
- What is the molecular structure of MES?
- What is the chemical reaction between MES and NaOH? What is the net ionic equation for this reaction?
- Before adding NaOH,
- What species are present in the solution?
- What are the resources for those species?
- What type of the solution is this solution?
- What is the pH of this solution?
- What species are present in the solution?
- 3.00 mL of NaOH have now been added to the MES solution.
- Which one is the limiting reagent for the reaction, MES or NaOH?
- What species are present in the solution?
- What are the resources for those species?
- What type of the solution is this solution?
- What is the pH of this solution?
- Which one is the limiting reagent for the reaction, MES or NaOH?
- 10.00 mL of NaOH have now been added to the MES solution.
- Which one is the limiting reagent for the reaction, MES or NaOH?
- What species are present in the solution?
- What are the resources for those species?
- What type of the solution is this solution?
- What is the pH of this solution?
- Which one is the limiting reagent for the reaction, MES or NaOH?
- 10.10 mL of NaOH have now been added to the MES solution.
- Which one is the limiting reagent for the reaction, MES or NaOH?
- What species are present in the solution?
- What are the resources for those species?
- What type of the solution is this solution?
- What is the pH of this solution?
- Which one is the limiting reagent for the reaction, MES or NaOH?
- Now more calculations on the pH of this titration have been calculated as below.
- Sketch a graph showing the pH of the system vs. the volume of NaOH added (all values are adopted from Daniel Harris Quantitative Chemical Analysis, 8th ed).
mL base added
pH
mL base added
pH
0.00
3.99
10.00
9.25
0.50
4.99
10.10
10.22
1.00
5.32
10.50
10.91
2.00
5.67
11.00
11.21
3.00
5.90
12.00
11.50
4.00
6.09
13.00
11.67
5.00
6.27
14.00
11.79
6.00
6.45
15.00
11.88
7.00
6.64
16.00
11.95
8.00
6.87
9.00
7.22
9.50
7.55
9.90
8.27
- Do you see different regions of this curve?
- Where is the equivalence point? What is the volume of NaOH at the equivalence point?
- Can you find out the pKa point for MES? What is the volume of NaOH at the equivalence point?
- What is the relationship between the volume of NaOH at the equivalence point and the volume of NaOH at the MES pKa point?
- Sketch a graph showing the pH of the system vs. the volume of NaOH added (all values are adopted from Daniel Harris Quantitative Chemical Analysis, 8th ed).
Summary of Titration of Weak Acid with Strong Base
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Contributors and Attributions
- Yan Liu, California State Polytechnic University, Pomona (yanl@cpp.edu)
- Sourced from the Analytical Sciences Digital Library