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.

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1answer
39 views

How is nitrogen gas passing through condensed water in the U-Tube while reducing metal oxides with ammonia gas?

In my school chemistry book, the experiment about the reduction of metal oxides with ammonia has a diagram of the set up as follows: $$\ce{NH₃ + CuO → 3Cu + 3H₂O + N₂}$$ The tube entering the U-tube ...
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2answers
46 views

Just looking for some help with finding relative ratios of components in a mixture using proton NMR

G'day, I am used to identifying molecular structure in isolation using proton and carbon NMR, but have never worked with a mixture before. The mixture relates to the following spectrum: The spectra ...
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0answers
27 views

Who originally invented Cathode Ray Tube? [closed]

While I was making my chemistry project on the topic "Cathode Ray Tube", I wanted to know the creator of it but while researching I didn't get any satisfactory result. Is there anyone who ...
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0answers
11 views

What is the effect of temperature changes on the following reaction: 2 SO2 (g) + 2 CaCO3 (s) + O2 (g) = 2 CaSO4 (s) + 2 CO2 (g) [closed]

What is the effect of temperature changes and why so? Equation: $$\ce{2 SO2 (g) + 2 CaCO3 (s) + O2 (g) -> 2 CaSO4 (s) + 2 CO2 (g)}$$
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0answers
28 views

Oils that penetrate the Dermis [closed]

Can u provide me with a list of oils that have molecules small enough to penetrate most layers of the dermis. And is sperimidine one of them. All carrier oils need not be listed.
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1answer
47 views

Tried dissolving the contents of a vit D3 capsule in MCT oil but it didn't work - why? (non-chemist here)

This is a question from someone who has no knowledge of chemistry whatsoever. So please bear with me. :) I'm a bit of a health and fitness fanatic, which is what led to my little experiment. I was ...
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1answer
26 views

What would happen if I increase the pressure and temperature of a gas present in a container

Assume the gas to be a real gas and the container to be made of diamond or anything stronger than that. Take the amount of gas to be 2mL and the pressure is increased with the help of strongest ...
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1answer
41 views

Method to remove impurities from acetaminophen synthesis experiment

I'd like to know about impurities from acetaminophen synthesis experiment. Are there any impurities produced by oxidation of p-aminophenol? If there is any impurity produced by oxidation of p-...
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0answers
54 views

Making synthetic moonstone using a HHO torch

I know we can make synthetic ruby using a HHO torch / oxyhydrogen torch and Aluminium Oxide + (video link below showing this along with the torch) https://youtu.be/7M4yqcO_pPo?t=450 But how does one ...
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0answers
27 views

Best practices to obtain small quantity of sealed solution without oxidising entire solution?

I'm ordering liquid based photo chemicals which only come in large bulk quantities. These solutions have a shelf life of approximately 2 years unopened, but 2 - 3 weeks once opened and oxidation kicks ...
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0answers
49 views

Why can't evaporation be carried out in an Erlenmeyer flask? [duplicate]

Our class was doing an experiment about the precipitation, filtration, and evaporation of potassium iodide and lead(II) nitrate. Our teacher said that we can't use the Erlenmeyer flask for evaporation....
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0answers
32 views

How to prepare an emulsion (compounds in wt%)

I am trying to replicate an experiment to generate microparticles but I found myself confused about how to prepare the ingredients as some need to be weighed and dissolved before and I think the ...
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0answers
37 views

Differences in activated manganese dioxide synthesis

I've looked into preparations of activated manganese dioxide for some time now, and what confused me is the contrast between the original Attenborough method and some of the alternatives. A solution ...
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1answer
56 views

NaOH + atmospheric CO2: Unexpected results troubleshooting

I've conducted an experiment where a solution of $\pu{4.2 M}$ $\ce{NaOH}$ was left exposed to atmospheric $\ce{CO2}$ for a period of time and titrated using potentiometric titration and potassium ...
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0answers
52 views

Analysis of reaction mixture by TLC and finding column chromatography condition

I am conducting an organic synthesis. Below is the TLC image. I used dichloromethane:methanol:triethylamine=10:1:0.15 as eluent, but I stored it during 3 days, so it may be a little bit concentrated. ...
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2answers
81 views

Why do alkenes (olefins) burn hotter than alkanes (paraffins), even though alkanes are denser and more hydrogen-rich?

Burning hydrogen releases more total energy than combusting carbon, and all alkanes are denser as well, so why are flame temperatures for alkene molecules higher than their equivalent alkanes? P.S.: ...
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1answer
76 views

Friedel–Crafts acylation of substituted anisole

I am attempting to form a synthetic route to a tetrasubstituted benzene compound. In the scheme, there is a step that requires the formation of a carbon–carbon bond in the C-6 position of a methoxy ...
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2answers
2k views

Which is a more accurate scale for a chemistry high school lab - a triple beam balance or a digital balance and why?

I would like to ask the experts of this chemistry community their opinions on which balance is more accurate and effective to use in a high school chemistry lab- a triple beam balance or a digital ...
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3answers
425 views

Choosing reaction stoichiometry in organic synthesis

Reading papers about organic synthesis, I see many cases like setting one material as 1.2 eq. I presume that reagents used more than 1 equiv are relatively inexpensive or less reactive than other ...
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0answers
52 views

How can I store reagent under inert gas?

I need to store some aliquots of 2,3,5-tribromothiophene. I searched for how to store reagent under inert gas, And I found this : https://avantilipids.com/tech-support/faqs/protect-from-oxidation In ...
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0answers
30 views

Problem about TLC solvent and staining

I am conducting an organic synthesis involving 1-aza-18-crown-6-ether. I tried TLC, but they didn't work well. I have tried: (1) hexane+ethyl acetate in various ratio, (2) dichloromethane:methanol=3:1,...
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0answers
20 views

Why does pure alpha glucose powder clump when attempting to dissolve in water and become very hard?

I noticed that when I attempted to dissolve some pure alpha glucose powder in water, it would become hard and clump at the bottom of the beaker if I dumped it into the beaker all at once. It was ...
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1answer
48 views

How Bread is made with yeast, sugar and luke warm milk? [closed]

Materials and Apparatus: wheat flour sugar dry yeast glass bowl covering plate milk Procedure: Lukewarm milk is taken in the glass bowl and sugar is added to it. Then, yeast is added to the same. ...
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1answer
52 views

Setting up reactor in inert atmosphere

I am searching for reactor set-up that can maintain inert atmosphere, and found that many organic synthesis labs use Schlenk line. But organic synthesis is not main thing of my lab, so there is some ...
2
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0answers
59 views

How to do a capacitively coupled electrode?

I have an AUTOLAB potentiostat: working electrode (WE, Pt wire), counter electrode (CE, Pt wire), reference electrode (RE, Ag/AgCl solid state). I would like to capacitively couple the potentiostat ...
3
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0answers
52 views

Purification of Buchwald-Hartwig amination

I am conducting a synthesis involving Buchwald-Hartwig amination. I use $\ce{Pd2(dba)3}$, $\ce{P(o-tol)3}$, and $\ce{Et3N}$ as base. In many proposed mechanisms, they often omit the precatalyst. I ...
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2answers
72 views

Should I do solvent extraction for Buchwald–Hartwig amination?

I am conducting a synthesis involving Buchwald–Hartwig amination. Catalyst is $\ce{Pd2(dba)3},$ ligand is $\ce{P(o-tol)3},$ base is $\ce{Et3N},$ and solvent is toluene. Image below is the proposed ...
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1answer
45 views

How to thermally insulate beaker glass on hotplate?

I bought a magnetic stirrer with a hot plate almost identical to this one. I am trying an experiment where I need to heat the beaker/mixture to about 100 degrees C. However the mixture/beaker is ...
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0answers
64 views

Is it possible to run column chromatography in reversed phase?

I'm conducting a synthesis involving aza-crown-ether. Whether aza-crown-ether acts as a base or not is unclear, but when I do TLC using dichloromethane/methanol, it is hardly drawn up with the mobile ...
2
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0answers
28 views

In cation analysis, can reagents of higher group precipitate lower group cations?

My teacher told me that Al$^{3+}$ and Zn$^{2+}$ hydroxides are frequently precipitated together and that is why we have to be careful about the concentration of base (NH4OH) added. Does this mean that ...
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0answers
43 views

Leakage during Celite filtration

I'm conducting a synthesis involving crown ether and Pd catalyst. In many papers, prior to column chromatography, they filter crude mixture through a Celite pad. I tried to, but leakage of Celite ...
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0answers
22 views

Is there a way to experimentally determine if a copolymer has a random monomer distribution or a blocky monomer distribution?

I prepared a styrene-butadiene copolymer with a polar modifier. The expectation is that the copolymer is "random". Is there a way to confirm this using standard characterization techniques?
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1answer
44 views

Using samples in titrations

I've never done an experiment before. So, the methodology provided in this pdf is quite confusing. Link to the pdf: https://www.canterbury.ac.nz/media/documents/science-outreach/vitaminc_iodine.pdf So,...
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1answer
69 views

How can I filtrate Pd2(dba)3 and P(o-tol)3? (Celite filtration failed)

I am conducting an organic synthesis involving Stille coupling, using $\ce{Pd2(dba)3}$ and $\ce{P(o-tol)3}$ as catalysts. Reaction solvent is toluene in which the catalysts also dissolve. Many texts ...
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0answers
46 views

what does Area(A) in Randles-sevcik equation refer to? geometrical area of electrode or electrochemical active surface area/

In the Randles-Sevcik equation, $$i_p = 0.4463 \ nFAC \left(\frac{nFvD}{RT}\right)^{\frac{1}{2}}$$ we have an area $A$ in the formula. is this the electrochemically active area or geometrical area? ...
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1answer
58 views

Why d and s orbitals overlap even when there is considerable difference in their energies?

In my grade 11 chemistry NCERT textbook, its written that hybridization happens when orbitals of almost same energy overlaps. But S orbital and D orbital have significant difference in their energies. ...
4
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1answer
71 views

Does pH gets affected by pressure? [closed]

My attempt- I thought that pH is h+ ion concentration and change in volume will change its equilibrium according to le chatelier's principle . But I want to know is it correct or it needs some ...
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1answer
69 views

How to make plasma in microwave (without grapes please)?

So, I have my School Science Fair next month. We are working in teams of five with one 7th, 8th, 9th 10th, 11th and 12th grader. We were planning to make plasma in microwave but the grape method just ...
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4answers
437 views

What's the purpose of significant figures in measurements?

I have read about significant figures in my chemistry and physics books, but none of them pointed out the significance of the significant figures. Searching the Internet I found two possible answers: ...
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2answers
99 views

What would happen if the alpha particles directly hit the electrons in the gold foil in Rutherford's experiment? [closed]

What would happen if the alpha particles directly hit the electrons in the gold foil in Rutherford's experiment? Would it get ionized or is there no probability of such a thing happening ?
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1answer
69 views

Is it possible to filter Stille catalysts using syringe filter?

I'm conducting an organic synthesis involving Stille coupling. Stille coupling uses $\ce{Pd2(dba)3}$ and $\ce{P(o-tol)3}$ as catalysts. Both catalysts dissolves in toluene which is the solvent of my ...
2
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1answer
54 views

Can the paper in thin layer chromatography be any type of paper?

I'm doing a chemistry chromatography lab that wants me to recreate anything I want. I decided to measure how far a pigment goes in each color for the same brand, but I'm stuck at the paper part. I ...
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0answers
29 views

Thickness of proton exchange membrane (Nafion)?

I am looking into using a proton exchange membrane for a bio-energy cell experiment. Previous scholars have been using Nafion as a PEM to place between the anode and cathode (air-cathode). the ...
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1answer
67 views

How to heat up a barrel drum? [closed]

I am experimentalist, and I am unsure on how to proceed about a question I have for an experiment. In the experiment, I would like to heat up a drum barrel like: It is made of HDPE, and I would like ...
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0answers
18 views

Can ethanol and heat during distillation cause degradation/dissolution of vinyl tubing leading hot vapors of the distillate to the condenser?

I'm a chemist and a qa lab, and we occasionally test herbal remedy products from one of our customers for alcohol content using a distillation, then using the specific gravity of the distillate to ...
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1answer
342 views

At which temperature does a concentrated aqueous solution of sodium chloride begin to boil? [closed]

We know, solutes dissolved in water increases the boiling point of water. This question is an MCQ. The options are 96,99,100,104 degree Celsius. The correct answer is 96. Why? If the boiling point ...
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0answers
31 views

Why is Retention factor for Iodide greater than Bromide?

I did a separation of Bromide and Iodide ions using paper chromatography technique for 0.3% solutions of Bromide and Iodide of sodium. I got the Retention factor equal to ~0.71 for Iodide and ~0.47 ...
3
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0answers
36 views

Why neglecting Bradford Solution Volume in the assay?

I would like to know why do we not need to take account of Bradford agent solution in dilution calculation? For example, $\pu{2.5 \mu g mL-1}$ BSA will calculate from $\pu{0.4 \mu L}$ of $\pu{1 mg mL-...
3
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0answers
43 views

Can color-changing leuco dyes be used to indicate when a certain molecule binds to another in a textile fabric?

Thermochromic leuco dyes change color when the temperature changes. I want to use leuco dyes to make a color-changing fabric. However, instead of using temperature to induce color changes, I want the ...
1
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1answer
34 views

Three Phases in TFM test instead of two

I am currently trying to perform the Total Fatty Matter (TFM) test on soap and for some reason I am getting three phases instead of two. The surfactant used is SLES and other reagents include hot ...

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