Questions tagged [analytical-chemistry]
The branch of chemistry concerned with identifying and quantifying the chemical constituents of matter.
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Iodine/iodide electrochemistry help
I have an electrochemistry experiment with iodine in solution.
I am initially wanting to quantify the iodide in solution and extrapolate the concentration of I2(aq) and I3-(aq) in solution from this ...
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Why are amber bottles used to store Water for HPLC?
Image Source: https://www.calpaclab.com/water-hplc-spectro-grade-4-liter-bottles-case-4/ted-ws2211-001
When ordering HPLC/Spectro grade Water for HPLC from certain vendors(not all), it comes in an ...
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What test would give me a qualitative recognition of the presence of benzene in methylphenidate?
I need a couple of tests to recognize the presence of benzene in my compound (methyphenidate).
I've looked into tests with bromide or Freidel-Crafts reactions but I'm not sure if both or neither would ...
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How to draw complex speciation diagram?
Given complexation reactions for a specific Metal $X$ and Ligand $L$:
$$
XL_i + L \rightleftharpoons XL_{i+1}, k_i = \frac{XL_{i+1}}{XL_i \cdot L}
$$
It's usual to draw a speciation diagram such those:...
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Why does my EBT indicator not turn pink in EDTA titration?
I am working on finding the calcium content lost upon cooking kale, using complexometric titration. For my indicator, I am using Eriochrome Black T indicator (EBT; solid form, not the liquid).
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user146547
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Experimental determination of ring strain energy
For my thesis I am looking to expand a part of it to include experimental means of calculating ring strain, thus far I have calorimetry covering heats of combustion and hydrogenation as well as ...
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Why is there a [M-1]+ in lieu of a parent signal in the Mass Spectrometry of Primary Alcohol Chains?
I have looked virtually everywhere for an explanation of why alcohols EI GC-MS always have a more prominent M-1 signal over a Parent chain signal--sometimes no parent signal at all.
One site says
http:...
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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 ...
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Meaning for chromatography terms linear velocity and volume flow rate
I am learning about chromatography and there are two terms that confuse me a lot: linear velocity and volume flow rate. These terms are defined in Daniel Harris's Qualitative Chemical Analysis:
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Does catechol give Tollens’ test?
Do hydroquinones like catechol or p-hydroxyphenol give Tollens’ test?
I know that β-diketones can reduce Tollens’ reagent to give a “silver mirror”, so I would guess that due to tautomerization ...
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Quantify below detection limit
If I want to detect a substance which is below the detection limit of my instrument, can I just add a known quantity and then quantify it?
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Atomization and excitation in AES
AES (atomic emission spectroscopy) is often mentioned as both quantitative and qualitative analyzing method. From this site Atomic Emission Spectroscopy the sources such as flame and ICP are used. ...
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An investigation on the rate of degradation (in %) of Chrysoidine-Y dye, as measured by UV-Vis spectrophotometry
Planning to do an investigation on the rate of degradation (in %) of Chrysoidine-Y dye, using UV-Vis spectrophotometry. I am planning to take an approach of increasing the concentration of Hydrogen ...
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How can I identify the material of this mystery gear?
I have this small gear which has sat on my desk for a couple years. I can't remember where it originally came from or what material it's made out of, so I'm hoping you can help me solve this mystery.
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Examples of compounds that are hard to ionise or which decompose easily upon ionisation in mass-spectrometer
From Chemistry LibreTexts — 4.11: Mass Spectrometry:
Limitations of MS generally stem from compounds that are not easily ionizable, or which decompose upon ionization. Geometric isomers can generally ...
