The branch of chemistry concerned with identifying and quantifying the chemical constituents of matter.

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Free Open Source Gas Chromatography Software

Collecting data is one thing, however sometimes one needs to plot or analyse data at a later date when access to the original software may no longer be feasible or possible. Open Source software is ...
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Is there open source software for SEM EDX data analysis?

This can't be unique to me and would apply to anybody who has to use equipment in other departments has had departments move etc. What open source packages exist to read and potentially manipulate ...
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13 views

What are some good references on conductometry as an analytical technique?

Non of the standard undergraduate textbooks in analytical chemistry (such as Skoog, Harris) discusses conductometry as an analytical technique. I wonder whether this technique is obsolete. Or is it ...
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What's the future of an organic and/or analytical chemist? [closed]

what can I do with a degree in analytical chemistry other than working in the lab? And what is the future of being an organic chemist? Can I be a researcher in both of them? Or it's better to take ...
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54 views

Can molecular structure be determined without modern characterization methods?

Molecular composition can be determined in some "primitive" ways (1, 2). What about the molecular structure? Is there a way to know what's bonded to what without spectroscopy etc.? By "modern" I mean ...
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58 views

I need to report MoS2 values from Mo and Sulfur numbers

I'm having a hard time figuring out how to do this and yes, I have the molecular weights, just don't know how to calculate. Been 20 years since college. EDIT: I'm working with Copper ores. One ...
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32 views

Identification of solutions by solubility when mixed with each other

$\ce{Pb^{2+} (aq), Cl- (aq), Ag+ (aq), (SO4)^{2-} (aq)}$. You number the four bottles, 1,2,3,4and while numbering them, you notice that bottles 1 and 3 have the word "cation" on their lids while ...
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122 views

Byproducts in Indigo Synthesis?

I have been messing around with making Indigo dye while waiting for bacteria to grow. I have been following the Baeyer-Drewson method. Basically, you mix nitrobenzaldehyde with an acetone water mix ...
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55 views

Reverse Phase Chromatography

Please help me figuring out what is going on with my RP-HPLC protocol. I am purifying a small peptide out of E.coli Culture, heat stable enterotoxin, its amino acid sequence is: ...
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Calculating Fluoride in toothpaste

I need help calculating the concentration of fluoride in toothpaste. Thanks in advance. A linear regression line was obtained; $$\log(\ce{[NaF]})~(\mathrm{mol~L^{-1}})~ \mathrm{vs~EMF}: y = 59.8x ...
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273 views

Why note the solvent level on chromatography paper when it is removed from the chamber?

Why is it important to mark solvent level on chromatography paper when you remove it from the chamber?
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Chromatography Separation Quantifying

This is a textbook question: "Suppose you are using chromatography to separate a mixture of two substances. Can you propose a means of quantifying how good or how poor the separation is?" So I got ...
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33 views

How to calculate mass of nanomaterial grown on a substrate

I'm growing graphene on copper substrates and need to know the mass. The graphene is grown via chemical vapor deposition; amounts of reactants are not completely known. The best approach I've thought ...
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54 views

How do I find the empirical formula for Co(C2O4)*H2O with mass of Oxalate and Oxide Product?

I have the formula $\ce{Co(C2O4)*H2O}$ in a reaction that forms cobalt oxide $\ce{Co3O4}$ – My data here says that my oxalate hydrate weighed 0.3283 g and my product oxide weighed 0.1158 g which I ...
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87 views

Near IR spectroscopy vs. IR spectroscopy

I am a backer of this Kickstarter: SCiO Near IR Spectroscopy Here is a link to their technology: SCiO Technology Question: How short of full IR spectroscopy do you think this device is? I have asked ...
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37 views

to convert ppm gas (N2O) concentrations in microgram nitrogen per gram dry soil basis?

What calculations are needed to convert $\ce{N2O}$ gas concentrations in ppm to micrograms of nitrogen per gram dry soil basis? I measured the concentration of $\ce{N2O}$ in soil samples. I extracted ...
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21 views

Determination of carbon content of steel by liquid chemistry

It seems like the typical laboratory methods for determining the carbon content of steel are to cuppellate it in a stream of oxygen and then measure the volume of the evolved $\ce{CO}$ and $\ce{CO2}$, ...
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27 views

Pb-based pigments and rhodizonate salts

In a previous question, I learned that we can detect lead with sodium / potassium rhodizonate, giving a nice purple color when reacting with pure (elemental?) lead. But in the paint, lead is ...
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83 views

Maximum observed optical rotation through a polarimeter

Is there a maximum optical rotation of plane polarized light that can be observed using a polarimeter? I understand that in a polarimeter, light passes through a filter that converts it into plane ...
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104 views

How to detect lead paint on a bicycle?

Recently I started renovating a bicycle. The frame has been painted probably over 30 years ago, and despite holding well, big patches of rust are showing. So it's time to give the bike a new paint ...
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111 views

What is the purpose of UV-VIS Spectroscopy?

I understand the purpose behind infrared spectroscopy and mass spectroscopy, but UV-VIS doesn't make much sense to me. Through research, I see that it has to do with electron orbitals, and it has a ...
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141 views

Phenyl group in proton NMR

Suppose you have this spectrum and the molecular formula of $\ce{C10H12O}$ The structure is My problem is with the peak at ~7 which is an H-Benzene signal, with quartet splitting and a relative ...
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170 views

How to analyze a acid and salt mixture using titrimetry?

Given a mixture of $\ce{HCl}$ and $\ce{MCl3}$ and the following dissociation constants for $\ce{M(OH)3}$, how can the concentrations of $\ce{HCl}$ and $\ce{MCl3}$ be determined separately by titrating ...
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28 views

solution concentrations [closed]

I think I'm making this more complicated than it needs to be, but here it is: I have 7 drug solutions, all 1 mg/mL which need to have the following concentration in urine: A: 25,000 ng/ml B: 25,000 ...
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43 views

Role of Acetonitrile and Ammonium Acetate buffer in Leucomalachite Green stock solution?

I am trying to repeat an experiment conducted by FDA on Malachite Green (MG). According to this paper, ...
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36 views

How are hormone levels measured?

I have been searching google and didn't found any links that describes how this process is performed - I mean the chemical procedure, not the process of taking the blood from the vein.
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Fertiliser analysis - Why doesn't it show ureic nitrogen when it does have urea?

I have had two types of urea fertiliser analysed, the results are as follows: $\ce{46\%N}$ (46% nitrogen) - which is sold as a urea fertiliser, tests at 46.1% ureic nitrogen. $\ce{38\%N 19\%S}$ (38% ...
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Choosing the instrumental techniques for chemical analysis [closed]

Since every technique has its goods and its bads characteristics, it's a bit hard for me to choose between them to determine specific elements, methods such as UV-VIS spectroscopy, IR spectroscopy, ...
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Qualitative spectrographic analysis

In order to identify the presence of a specific element, one must identify at least three ultimate lines of that element in the specter. Those lines are the ones with the highest intensity. I ...
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Know any micropipettor that is acid resistant?

We pipet concentrated nitric and hydrochloric acids. our current pipettor is rainin lite but its piston is metal and thus corrode easily. We discussed this with our inhouse technician and he ...
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34 views

What is the mechanism for electrospray ionization?

I've been asked to Descibe the ionization mechanism used in electrospray ionization I know that this is a desorption ionization source, which uses a high electrical field as the ionizing ...
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86 views

Estimate the concentration of HCl and volume of 6 M HCl required to complete precipitate each of the given salts

In our chemistry lab we performed the following experiment below. Given that $K_\mathrm{sp}(\ce{AgCl}) = 8.2 \times 10^{-11}$ and $K_{\mathrm{sp}}(\ce{PbCl_{2}}) = 1.7 \times 10^{-5}$ ...
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What are some books, websites, etc. where I can find the detailed protocol for standardization of sodium thiosulfate with dichromate?

I am looking for a book or website such as "Vogel's Textbook of Quantitative Chemical Analysis" where I can find methods for analyzing/standardizing a particular species easily. I am not looking for ...
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48 views

2,4-dinitrophenyl hydrazine test

I found this reaction over here: which illustrates the carbonyl test but looks fuzzy. Assuming that the R in the product is a typo for H, I couldn't conserve the number of Nitrogen atoms. ...
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Is the following reaction redox? [closed]

Is the test of sulphur using sodium nitroprusside a redox reaction?
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31 views

Stability constant of complexes

I know that this constant tells us the strength of the interaction between the metal and the ligand, so should it also mean that the higher the constant, the stable the complex ? I need to make sure ...
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Different elution profiles of carvacrol and thymol

I have identified carvacrol and thymol via thin-layer-chromatography and via gas chromatography On a normal silica plate the thymol has a higher Rf-value then carvacrol. The explanation for this would ...
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Photometric titration

If we have $\ce{A + T -> P}$ where $\ce{A}$ is the analyte, $\ce{T}$ is the titrant, and $\ce{P}$ is the product, photometric titration happens only in one condition, that one of the following ...
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Optional determination techniques in AAS

I have tried to find information about this case but I couldn't find anything specific. The key point of instrumental methods of analysis, is for the student to be able to know which one of the ...
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59 views

Determination of mercury in AAS

Its known that the only method to determine mercury in atomic absorbtion spectroscopy is the cold vapor method. What is the reason that mercury can't be determined with other methods, such as flame, ...
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How to confirm the type of bonding taking place between two substances?

For example ink on paper: how can I confirm that the bonding is van der Waals and not covalent? Similarly, the same question can be asked about other interaction such as hydrogen bonding, ionic ...
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333 views

Converting g/L to mol/L

I know I should divide $\mathrm{g~L^{-1}}$ by the molar mass of the substance, but I don't seem to find the specific answer on Google. So just to be sure: If I have ...
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Atomizers in AAS

Electeothermal atomizer ( graphite furnance ) and flame atomizer, are the instruments which help us to convert the analyte into the gas state and they both achieve that. My question is, what's the ...
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Manuals for a Cahn TG-171 Thermogravimetric Analyzer

Recently a Cahn TG-171 Thermogravimetric Analyzer was donated to my school. We did not get a service or user's manual with it, and some of it still needs to be put back together. I have tried to ...
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93 views

How does standardising a secondary standard solution make it suitable as a standard solution?

I know that a standard solution in volumetric analysis must have an accurately known solution. Primary standard solutions (e.g. anhydrous sodium carbonate) can be used straight-away as they follow the ...
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72 views

Identify this solution

The solution is emerald green in colour. When added with water, it gives a pale blue solution When reacted with $\ce{BaCl2}$, it gives a sky blue solution and a white precipitate. When reacted with ...
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42 views

Wavelength extention in AAS

Theoreticly, the width of the spectral line in AAS (atomic absorbtion spectroscopy) is 10^-5, but in fact there happens an extention of it and it becomes 0.002-0.005. There are some factors which ...
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72 views

Way to detect lead in gasoline

Is there any way that i can detect lead in gasoline, not by sending of to a lab but to be able to do this by myself?
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How is drift due to static electricity eliminated from an analytical balance?

I've recently encountered a problem when using an analytical (0.1 mg accuracy) scale to determine the mass of a sample of ferrocene powder. The reading in the balance seems to drift either upwards or ...
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Auxochrome groups

Functional groups like $\ce{OH}$, $\ce{NH2}$, attached to nonsaturated compounds (chromophores) are called auxochromes. These groups tend to shift the wavelength to the infra-red area which is called ...