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Questions tagged [henderson-hasselbalch-equation]

-2 votes
1 answer
122 views

Sodium Citrate / Sodium Phosphate Buffer Calculations

I'm trying to work through the calculations of a specific paper (linked here / below) but, my numbers are way off and I can't get them to match for the life of me. I need to make the same buffer but ...
user136195's user avatar
1 vote
1 answer
216 views

Henderson-Hasselbalch equation and degree of dissociation

Is it possible to evaluate the degree of dissociation in unbuffered solutions, through the Henderson-Hasselbalch equation? For example: place acetic acid in a sodium hydroxide solution. After the ...
Luckenberg's user avatar
2 votes
0 answers
52 views

Which pKa should I use in this Henderson/Hasselbalch rearrangement?

I have a question about the following formula: $$Mu/Pu = \frac{1+10^{pHm - pKa}}{1+10^{pHp- pKa}}$$ This formula can be found in the following paper: Begg, E. J., & Atkinson, H. C. (1993). ...
Sjoerd 's user avatar
3 votes
0 answers
78 views

Measuring [A-]/[HA-] with Buffer and Indicator

I'm very confused on how to calculate the [A-]/[HA] value, given the fact that my dilution series uses buffers at various pH values with the same indicator (supplied at the same concentration to each ...
Tyler Anderson's user avatar
0 votes
0 answers
1k views

How to calculate a citric acid and trisodium citrate buffer?

I am trying to calculate how to prepare 500 mL of a citric acid (H3Cit) and trisodium citrate (Na3Cit) buffer with a pH = 4.5 and a total concentration of 0.1 M. I know that it is necessary to use the ...
camibuidi's user avatar
2 votes
1 answer
2k views

Slope ≠ 1 in Henderson-Hasselbalch graph for determination of pKa

The $\mathrm{p}K_\mathrm{a}$ of indicators can be determined via plotting a graph of $\log \left(\frac{\ce{In-}}{\ce{HIn}}\right)$ vs $\mathrm{pH}$ with the help of a spectrophotometer, from the ...
Owen 's user avatar
  • 21
1 vote
0 answers
321 views

Henderson-Hasselbalch approximation

The Henderson-Hasselbalch approximation gives us a method to approximate the pH of a buffer solution. The basic equation is as follows: $$\mathrm{pH} \approx \mathrm{p}K_\mathrm{a} + \log\dfrac{\ce{[A^...
Aladdin's user avatar
  • 303
1 vote
1 answer
2k views

Derivation of Henderson–Hasselbalch equation

While deriving the Henderson–Hasselbalch equation why don't we consider the hydrolysis reaction? For example if we consider an acidic buffer of acetic acid and sodium acetate, why do we not consider ...
rohit_r's user avatar
  • 329
9 votes
3 answers
6k views

Is the Henderson–Hasselbalch equation volume independent?

Looking at this equation $\mathrm{pH} = \mathrm{p}K_\text{a} +\log\frac{[\ce{CB}]}{[\ce{A}]}$ makes me think that it is concentration independent. What I mean is, when we look at $\frac{[\ce{CB}]}{[\...
Tony's user avatar
  • 91
5 votes
1 answer
2k views

How to calculate the pH of a buffered solution with Henderson Hasselbalch?

Lets say you have a buffered solution containing $0.50~\mathrm{M}$ acetic acid ($K_a = 1.8 \cdot 10^{-5}$) and $0.50~\mathrm{M}$ sodium acetate, and you want to calculate the $\mathrm{p}\ce{H}$ of ...
1110101001's user avatar
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