Questions tagged [experimental-chemistry]
This tag should be applied to questions relating to the theory, design, techniques or performance of chemical experiments. This includes but is not limited to theoretical structures, expected products, thermal calculations, and empirical analysis. Additional tags should be applied to narrow down the field of research.
1,734
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Is bad to inhale the fumes of ammonia? [closed]
In my gen chem lecture he was teaching us about how different reactions deal with heat. I went up and was told to keep on mixing the two elements that he put in there. I was mixing and breathing it in ...
0
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0
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32
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Using potassium thiosulfate instead of sodium thiosulfate in iodine clock reaction
I am familiar with the iodine clock reaction that uses sodium thiosulphate. Still, I'm wondering if I could use potassium thiosulphate instead, as it's the thiosulfate that reduces the Iodine.
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Which paint can be detected by camera in broad daylight [closed]
Railway carriages have air brakes and suffer from unintended brake application due to human error. Which causes loss of time in train operations and sometimes fires in brake pads.
Some carriages have ...
7
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1
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677
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What is laboratory air?
Oftentimes in the literature, particularly for oxidation studies, the authors mention that experiments were performed in "laboratory air." Is there any distinction from laboratory air from ...
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I need to know the percentages of each component in a dishwashing liquid [closed]
I'm required to make my own dishwashing liquid but I need the help of an expert to exactly know the percentages of each component in a dishwashing liquid, specifically a 500ml one
Here are the ...
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ACETONE-ETHANOL BINARY SYSTEMS EXPERIMENTAL VLE DATA AT PRESSURE NOT EQUAL TO 1 atm [closed]
Basically, we're tasked to find for experimental vle data for acetone(1)/ethanol(2) system at a specific pressure that is not equal to 1 atm. Maybe you could me find studies relevant to this, thank ...
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1
answer
61
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Why potassium carbonate breaks glass when heated? [closed]
I have been studying about desiccants for a while and testing some inorganic salts, including calcium chloride, sodium sulfate and potassium carbonate. When they get enough moisture from air, I ...
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1
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In JJ thomson's cathode ray experiment why is the effect of gravity on the electron not considered? [closed]
Explaining the setup:
The experiment is described in the picture.
Instead of the magnets in the picture imagine two circular coils on both the sides with current running through it, this creates a ...
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2
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Tollen's Test - Clean Up
In school, we had an experiment to find out the biomolecules contained by the different food-stuffs. After doing Tollen's test which turned out to be positive, our teacher instructed us to clean the ...
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Does acetone react with acidic precipitate product in this reaction?
In this reaction procedure, It seems like there is a mistake in step 3 which would result in a 0% yield. From step 3, it looks like everything is fine, its performing the acid catalysed hydrolysis of ...
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why are there no pictures or experiments on solid ozone?
wikipedia states that solid ozone is violet black in colur and so is my textbook, but when you search up for solid ozones, there are no pictures or experiments done in youtube. Was the colour or the ...
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What's the practical use-cases of Raoult's Law?
So, I am taking my first chemistry class and I started learning about Raoult's Law and it states that, when a non volatile solute is added to a solvent, the vapor pressure of the solvent decreases in ...
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1
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Understanding Rossini and Frandsen experiment for measuring $(\partial u/\partial P)_T$?
In another question, I asked about the theoretical justification for the experiment that I will describe in what follows.
The experiment was done by Rossini and Frandsen in 1932 at the National Bureau ...
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2
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51
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High-temperature interactions with salts on nichrome wire
I'm working on creating aluminium-doped zinc oxide (AZO) thin films, but instead of the usual glass substrate, I want to try this on a fine nichrome wire.
I'm using a mix of zinc acetate $\ce{Zn(...
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1
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using either 2-propanol or isopropyl alcohol for writing a report
I'm writing a report based on testing I've done on a material. I'm wondering if there is any convention on using different nomenclature for isopropanol. Which way of writing this molecule is consider ...
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Why did this synthesis of Aspirin fail?
I tried to synthesize acetylsalicylic acid(aspirin) by the method below. However, I definitely failed and got something unknown.
The method used was:
Add 2.5 g of salicylic acid(about 2494 mg), 3.0 ...
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1
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1
answer
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What does it mean if a calibration curve regression doesn't cross (0,0)
I have been taking many lab courses in my second year of university and I have come across the technique of creating a calibration curve quite a bit. One thing I noticed in a lot of my plots is that ...
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3
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Storage of air and temperature sensitive reagents
What's your method for storing air/moisture and temperature sensitive reagents? For example:
A solid. Should I just blow some argon, screw the lid, put parafilm and put it in the fridge? Can a ...
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3
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1
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312
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How can I read an Anschütz/Bennert manometer and how can I make sense of it?
Recently I have come across a mercury-filled manometer for vacuum distillation that somewhat resembles a U-tube shaped manometer, but with one arm sealed and completely filled with mercury. Searching ...
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1
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How to produce Fe(OH)2? [closed]
I'm interested in producing Ferrum hydroxide (II), I did some research on the internet and made a plan for myself:
Conduct electrolysis:
Conduct electrolysis producing $\ce{NaOH}$ and chlorine ...
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1
answer
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Why ordinary oil was not recommended in Millikan oil drop experiment?
Why was it recommended not to use ordinary oil in Millikan oil drop experiment? What were the properties of oil used by Millikan?
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1
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Help with Calcium Alginate Precipitation
I am a high school student working on a research project that involves producing alginate gel directly from wet seaweed. I am starting the first phase next week, which is using a small batch to ...
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3
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Can pure hydronium exist?
Can pure hydronium exist? If not, why not? It seems to me (and I am no chemistry expert) like pure hydronium should have the theoretical maximum acidity or minimum pH that a substance can reach.
Can't,...
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2
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Soil chemical Anaylsis/CAL-P
I have added two levels of Phosphorus (P) to the soil, one at 30 mg/kg and the other at 130 mg/kg, representing low and high P levels, respectively. After thoroughly mixing the fertilizer with the ...
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2
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1
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pKa and pKb in solvents other than water
I know that when you have aqueous solutions, then the pKa and the pKb are linked to each other (pKa + pKb = 14). Is there an equivalent relationship between pKa and pKb in non aqueous environments? I'...
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1
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268
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How can I avoid magnesium smoke during melting? [closed]
I am trying to make a magnesium-nickel alloy. I carry out the melting process in an inert gas, but during the process, the magnesium smokes. What can I do?
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2
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I need help for my chloride titration
I'm a 14-year-old student embarking on my first chemistry assignment. My teacher has tasked me with conducting a chloride titration of drinking water. There's just one condition: I must avoid using ...
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0
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Addition of NaCl to the Anode Side of a Zinc-Copper Votaic Cell
I used a NaCl solution with a Zinc electrode in an otherwise standard voltaic cell with a Potassium Nitrate Salt Bridge and Copper Sulfate solution in the Cathode side. All the solutions were 1M.
I ...
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THF-H2O mixture at 80°C? isn't THF supposed to evaporate completely?
I was running a synthesis of TiO2 nanoparticles starting from a aqueous solution of TiCl4 2THF 0.125M at 80°C. Through a different experiment it was detemined that the maximum reaction yield was 96% ...
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2
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Determining weight to within 0.1mg? [closed]
For a recent laboratory session we were asked to weight a 20mL beaker three times on an analytical scale. Each time, we were asked to determine the weight to within +/- 0.1mg. I am just a little ...
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1
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Would having a greater H-bond donor count make a substance more readily enter a twig?
Yes, weird plant scientist asking weird plant questions...
Background:
I am looking at how the twigs of trees absorb water, a poorly understood means by which trees alleviate water stress. Of 4 ...
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3
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Voltammogram during calibration is not smooth
During calibration for differential pulse voltammetry, the voltammogram obtained has two distinct peaks. I am not sure why I am getting two peaks in the range from $\pu{-0.6 V}$ to $\pu{-0.9 V}.$ I ...
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1
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What meaning does Gibbs energy acquire when applied to solutions?
I have been picturing functions like enthalpy and Gibbs free energy as mathematical tools, which were defined in such a way as to be useful for some specific cases. I understood enthalpy as a useful ...
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4
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Drying salts with HCl solution
I'm following a protocol from some old literature (1962), and I want to make sure I'm being safe. It asks you to dissolve some salts in 150 mL water + 25 mL concentrated HCl, then evaporate to dryness ...
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4
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1
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What kind of adhesive could I use as a binding agent for calcium chloride?
I want to create a paper-thin layer of calcium chloride. This sheet should still be capable of absorbing water and allowing gas to permeate downward when it becomes saturated with water and is exposed ...
6
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2
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Rutherford's gold foil experiment thin sheets
I am struggling to understand why Rutherford needed to use extremely thin sheets in this experiment. I understand that gold was used, as it was relativley easy to achieve these thin sheets, but why do ...
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Why does copper(II) sulfate or iron(III) nitrate work as a catalyst for the iodate variant of the Iodine Clock?
In the iodine clock reaction (iodate variation), the reaction of iodate and bisulfite ions apparently is the rate-determining step. I was wondering if $\ce{Cu^2+}$ and $\ce{Fe^3+}$ will act as ...
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How can I dissolve my Copper(II)sulfate in my MOPS buffer pH 7.2?
For my research project I need to analyze a copper-ligand complexes in a basic buffer through UV-Vis spectroscopy. After testing several buffers, I currently use the MOPS buffer which I want to adjust ...
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1
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1
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Term for one chromatography sample affecting the next?
Suppose I am running a collection of samples on a chromatograph (gas or liquid) in some order. Some of the sample molecules have large retention times due to their size and/or interactions with each ...
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0
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Rate of SN1 reaction in derivative of furan and thiopene
When I was practising questions on the rate of SN1 mechanisms, I stumbled across this:
I could eliminate options B and D because they can stabilize by only cross conjugation (if I am correct) and ...
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4
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How to distinguish silver chloride, bromide and iodide?
When we test for chloride, bromide and iodide ions we use the obvious silver nitrate and dilute nitric acid test. However distinguishing between the precipitates is often quite tricky. How can we tell ...
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1
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Confirmatory Test for Chitosan
Okay heres my problem. I cannot find this procedure online, can someone please help me?
Confirmatory Test for Chitosan Reagents and materials: Iodine/Potassium iodide (0.2 g iodine are added to 100 ml ...
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1
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Help explaining drug packaging, "Bromocriptine Mesylate equivalent to Bromocriptine 2.5 mg"
API for Bromocriptine Mesylate is currently quoted by manufacturers as 2x the price per gram that we can get it already in pills and packaged in the retail pharmacy. This doesn't make sense to me... ...
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1
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How to determine uncompensated or solution resistance of a 3 electrode setup for IR correction?
To correct for ohmic losses from the potential drop across the electrolyte due to the distance between the electrodes, electrochemical impedance spectroscopy (EIS) is typically employed to measure ...
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1
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1
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Production SnO2 nanoparticles through chemical co-precipitation method: chemical equation of the reaction
In this paper, the production of $\ce{SnO2}$ nanoparticles through the chemical co-precipiation method is described using $\ce{SnCl2·2H2O}$ as a precursor. According to their experimental section,
$\...
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0
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Problematic Menshutkin reaction
I'm quite new to organic chemistry and want to try menshutkin reaction. Like the reaction in an attachment.
I use that recipe:
I do everything in a 60ml beaker. I dissolve 18 mmol of pyridine in 35 ml ...
2
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1
answer
106
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Reduction of La(NO3)3 to La(NO2)3
I'm writing a master's thesis on some lanthanide compounds, in particular those with $\ce{Ce^{+3}}$ and $\ce{La^{+3}}$, although my focus has now shifted to lanthanum, but I ran into a problem when I ...
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betamechaptoethanol smell [closed]
I am doing my masters in science and today one of our neighbors from the other lab came to heat his samples on a heating pad. the samples were in small tubes which contained Betamechaptoethanol, when ...
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1
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How do I synthesize salicylic acid?
I'm looking to synthesize salicylic acid in my school laboratory for an investigatory project. The Kolbe's reaction looks promising:
Any suggestions on where to get the $\ce{CO2}$ from?
Will the ...
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1
answer
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How Can the First Ionization Energy of Helium be Accurately Calculated Using Basic Quantum Mechanics?
How Can the First Ionization Energy of Helium be Accurately Calculated Using Basic Quantum Mechanics?
There is a book which summarizes the fairly accurate calculation of the First Ionization Energy of ...
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