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What is the effect of pH on absorbance in spectrophotometric titration?
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+ Analytical chemistry
+ Titration
+ Chemistry
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Nicole DeKay
What is the effect of pH on absorbance in spectrophotometric titration?
In acid-base titrations an indicator, that changes color is used. During titration the pH changes, so does the color of the indicator. If there is a color change in a titration, why not couple it with spectrophotometer?
In acid-base titrations an indicator, that changes color is used. During titration the pH changes, so does the color of the indicator. If there is a color change in a titration, why not couple it with spectrophotometer?
That will absolutely depend on what the compound is. For many compounds, pH will have absolutely no effect on the absorbance of the compound. For some compounds which are either weak acids or weak bases, the protonated and unprotonated forms of the compound have very different spectra. So, as the pH changes, the amounts of the protonated and unprotonated forms of the compound change. This will alter the absorbance of the compound at certain wavelengths.
That will absolutely depend on what the compound is. For many compounds, pH will have absolutely no effect on the absorbance of the compound. For some compounds which are either weak acids or weak bases, the protonated and unprotonated forms of the compound have very different spectra. So, as the pH changes, the amounts of the protonated and unprotonated forms of the compound change. This will alter the absorbance of the compound at certain wavelengths.
In acid-base titrations an indicator, that changes color is used. During titration the pH changes, so does the color of the indicator. If there is a color change in a titration, why not couple it with spectrophotometer?
In acid-base titrations an indicator, that changes color is used. During titration the pH changes, so does the color of the indicator. If there is a color change in a titration, why not couple it with spectrophotometer?
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That will absolutely depend on what the compound is. For many compounds, pH will have absolutely no effect on the absorbance of the compound. For some compounds which are either weak acids or weak bases, the protonated and unprotonated forms of the compound have very different spectra. So, as the pH changes, the amounts of the protonated and unprotonated forms of the compound change. This will alter the absorbance of the compound at certain wavelengths.
That will absolutely depend on what the compound is. For many compounds, pH will have absolutely no effect on the absorbance of the compound. For some compounds which are either weak acids or weak bases, the protonated and unprotonated forms of the compound have very different spectra. So, as the pH changes, the amounts of the protonated and unprotonated forms of the compound change. This will alter the absorbance of the compound at certain wavelengths.
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