All Questions
Tagged with aqueous-solution analytical-chemistry
50
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How to dissolve a powdered drug once it has been mixed with water
For a biological experiment I have acquired $\pu{10 mg}$ of CHIR 99021 (laduviglusib). In order to obtain a $\pu{10 mM}$ stock solution, I had to dissolve the powder in $\pu{2.15 mL}$ of dimethyl ...
- 19
2
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63
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Stability of n-Dodecyl-beta-D-maltoside in buffer solutions for assay experiments
I have a buffer system which contains multiple salts and in addition DTT and n-Dodecyl-beta-D-maltoside.
I understand that DTT is hydrolysing quite fast and this component must be used always fresh ...
- 779
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70
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What does it mean for a substance to be "sparingly soluble"?
I have trouble understanding what solubility means. Merriam-Webster defines it as follows:
1 the quality or state of being soluble
2 the amount of a substance that will dissolve in a given amount of ...
- 67
2
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1
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84
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Are all salts completely dissociated in solution when put in smaller amounts than their molar solubility?
From what I understand, the solubility is given in terms of molar solubility (or $\pu{K_{sp}}$), from which it can be easily calculated). Indeed, the saturation point represents the maximum amount of ...
- 67
1
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2
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180
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What is the inconsistency in calculating the differences in Na2O and NaOH in solids (v2)?
(Note that this question has been fully edited for clarity, SE help advised not to delete the question and post another).
Background:
I have a computer model in which I feed it input data from various ...
- 500
4
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4
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244
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Determining the concentration of a very small sample of sulfuric acid
How can we determine the concentration of sulfuric acid in a very small sample?
We are working on a “mechanical” process that transports a very small amount of sulfuric acid to an instrument and we ...
- 41
3
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2
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1k
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Magnesium vs calcium vs barium ions from these 3 tests
How do I pick up the difference between barium, calcium, and magnesium ions? I had to do a quantitative analysis practical exam: I was given an aqueous solution of a salt, and when adding separately ...
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Determining iron(III) content in mixture of iron(II) and iron(III) [closed]
Problem
Outline a plan of an experiment to determine the percentage of iron present as iron(III) in a solution containing $\ce{Fe^3+(aq)}$ and $\ce{Fe^2+(aq)}$ ions. You are provided with zinc, a ...
- 15
1
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1
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70
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An Index Poisoning Case Involving Dichlor and Carbonic Acid [closed]
I'm currently working an unusual case of poisoning, with Sodium Dichloro-S-Triazinetrione.
In my case, I need to know the expected reaction with carbonic acid.
I'm also curious if anyone could give ...
- 11
3
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1
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580
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pH meter mechanism - connecting potential differences
This question was asked here: pH probe bulb - what is happening within the glass? and How does a pH glass electrode work?.
But, the mechanism remains unanswered. How does a potential difference ...
- 39
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1
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38
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Disparity between LeChatelier's Principle and Solutions
Let's say that there is a solution
$\ce{Na+(aq) + Cl-(aq) <=> NaCl(s)}$
If the above solution is at equilibrium we can say that it is saturated and hence no more Sodium Chloride will dissolve. ...
- 151
0
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138
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Problem in the calculation of ionic strength of a solution
Recently I've been trying to answer the question 10-13 (c) of 9th edition of Fundamentals of Analytical Chemistry of Skoog et al. Comparing my answers with the student manual , I realized that my ...
- 177
1
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84
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Alkalinity measured by titration after degassing of CO2
I recently received some lab results from a sample which contained a lot of CO2, which degassed before the total alkalinity was measured by titration to a pH 4.5 end point. The best analogue for this ...
- 31
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Determining the mass of a substance using calibration curve produced by HPLC
I hope everyone is doing well and safe! Yesterday, I was fortunate enough to be taught about how to read a chromatography calibration curve through this stackexchange! Special thanks to those who ...
- 87
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Can analytical precision be finer than a lower detection limit?
Can analytical precision be finer than a lower detection limit?
For example, if the lower detection limit of an analytical method is reported as 0.010 ppm. Is it possible to have an analytical ...
