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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2
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0answers
43 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 ...
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0answers
29 views

how is glow in the dark phosphorescent made? [closed]

what makes the glow more brighter than ever?
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0answers
39 views

Chemistry Equations [closed]

How do I know what the equation of a reaction is without knowing what the products are? Am i meant to do trial and error and just guess? Eg: When 3.4g Pentane was burnt in excess oxygen, 165kJ of heat ...
3
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0answers
46 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 ...
4
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2answers
60 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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0answers
16 views

Question about Oxygen Managment [duplicate]

I am working on ideas for a more hard Si-Fi, and I am wondering through what processes one could theoretically take the carbon dioxide we breath out and break it down into Carbon and Oxygen. I am ...
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1answer
40 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 ...
1
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0answers
47 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 hardly goes up. (see image below) ...
2
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3answers
174 views

Disposal of Silver Halides dissolved in Ammonium Hydroxide

I was reading the Lab Manual for Chemistry prepared by the NCERT . While going through the the test for Chloride ions (pg 88) I came across the following Hazard Warning : The solution obtained after ...
1
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1answer
114 views

Separation of methanol–water mix in a plate distillation column

I conducted an experiment to separate methanol and water. I am trying to determine the mole fraction of the distillate collected but having a little trouble with the calculation. The flow rate was $\...
2
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0answers
24 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 ...
0
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1answer
54 views

steam distillation vs fractional distillation

I am a high school student and I am a little confused in the techniques used to purify organic compounds, for e.g we study in steam distillation we reduce the external pressure on the compound to be ...
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0answers
38 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

Why does iodine to give off so much vapour? [duplicate]

It is reported that when placing iodine in a breaker and letting it sit, over time the iodine will slowly give off a large amount of vapour. The question is why does it give off so much vapour. I was ...
2
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2answers
197 views

Query in Chemical Kinetics

I have been recently studying chemical kinetics. I've understood what the rate law and the rate constant mean, and also that, kinetics depends completely on experimental observations, due to which we ...
2
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0answers
18 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?
2
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1answer
119 views

Organic solvent for cleaning autosampler syringe

I work in a laboratory where gas chromatography is used extensively. We handle phthalates. What are the possible wash solvent for autosampler syringe? I've been using acetone.
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1answer
43 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,...
1
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1answer
127 views

Is it possible to make a solution of zinc oxide in a high school chemistry lab?

As part of my IB Chemistry curriculum, we are required to conduct our own experiment researching our own question. I'm in the preliminary research phase and wanted to conduct an experiment looking at ...
4
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0answers
5k views

Role of hydrochloric acid and sodium hydroxide in isolation of citric acid from lemon juice

I'm trying to extract citric acid from squeezed lemons. After studying the subject, I found a lab manual [1, p. 68]: ISOLATION OF CITRIC ACID Reagents: Lemon juice (ca. $\pu{100 mL}$ – 3 lemons) $\...
1
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1answer
69 views

BPS & BPA treatment with 80% Ethanol

Background: BPA and BPS (Bisphenol A/S) are artificial estrogens and therefore toxic chemicals for us. They are used in the coating of thermal paper. Thermal paper is used to print in-store receipts. ...
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0answers
31 views

What's the right way to prep anhydrous potassium ferrocyanide from potassium ferrocyanide trihydrate?

Orgo student here. I've got some potassium ferrocyanide trihydrate I tried dehydrating with no success. I put 20 g of potassium ferrocyanide trihydrate into a 30 mL crucible driven up to 150 C for 2 ...
3
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1answer
905 views

Mixing oxalic acid and glycerin

I am doing an experiment for a miticide for honey bees. I will be dissolving 600 g of 99.6 % oxalic acid in one liter vegetable glycerin at 150 °F (65 °C). I have been told it will give off formic ...
3
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1answer
107 views

Removing Iron Oxide from a Floppy Disk?

Don't ask me why, but I did an experiment where I tried to remove the magnetic iron oxide layer from a floppy disk by soaking it in HCl for a week. I put pieces of floppy disk in 0 - 1 M HCl, then ...
7
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1answer
804 views

Why does thallium hydroxide increase the yield of product in a Suzuki reaction?

I came across a research paper by Uenishi et al. [1] where relative rates of $\ce{KOH}$ and $\ce{TlOH}$ in Suzuki coupling reactions are compared. Thallium hydroxide increased the yield of products, ...
36
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10answers
7k views

Why is chemistry unpredictable?

Disclaimer: I am not a chemist by any means, and I only have knowledge limited to what I learned in my university's Chemistry III course. Basic understanding of everything up to valence electron ...
7
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4answers
244 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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1answer
65 views

Detection of sulphide in solution also containing sulphate

Question: The reagent(s) that can selectively precipitate $\ce{S^2-}$ from a mixture of $\ce{S^2-}$ and $\ce{SO4^2-}$ in aqueous solution is(are): (A) $\ce{CuCl2}$ (B) $\ce{BaCl2}$ (C) $\ce{Pb(...
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1answer
197 views

How do I find the final concentration after an additional dilution?

I took poor notes and didn't record what the final concentration of an amylase solution I made last year. I recorded that I took $\rm 0.2\ g/10\ ml$ of the amylase solution, and then took $\rm 1\ ml$ ...
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1answer
59 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 ...
0
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1answer
2k views

How to calculate the volume of oxygen in a reaction between hydrogen peroxide and bleach using this apparatus

I know that the reaction between bleach and hydrogen peroxide produces oxygen but using this apparatus and information, I need to state how to calculate the volume of oxygen released: At the start of ...
6
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1answer
17k views

HPLC: peak area vs concentration

Many text books say that there is a proportionality between the peak area of the chromatogram and the concentration. However, in my opinion, there should be a proportionality between the concentration ...
4
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1answer
67 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 ...
5
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0answers
42 views

Why is surface tension of water decreasing as sodium chloride concentration increases? [duplicate]

For my IB chemistry IA, I am measuring the impact of salinity concentration on the surface tension of water (i am using distilled water). My hypothesis is: As the concentration of salt increases, ...
2
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0answers
42 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
1k views

Does Glycerol give silver mirror test with Tollen's Reagent?

I did an experiment in my school lab in which we had to identify the given organic compound. In my Lab Manual, it's written: Take 2 ml of Tollen's Reagent and add a few drops of organic sample. ...
1
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1answer
50 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. ...
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1answer
66 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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2answers
87 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
65 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 ...
2
votes
1answer
51 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 ...
2
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1answer
59 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 ...
3
votes
1answer
556 views

What is the state of stationery phase in paper chromatography?

As per my textbook: Partition Chromatography: Partition chromatography is based on continuous differential partiotioning of components of a mixture between stationary and mobile phases. Paper ...
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0answers
27 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 ...
3
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1answer
4k views

Iodine clock reaction

I have been investigating the iodine-clock reaction for my chemistry project. I have done a great deal of research on the titration of iodate ions, iodide ions and sodium thiosulfate using HCl. But, I ...
0
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0answers
16 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 ...
7
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1answer
1k views

Is it possible to chemically treat grass to make it digestible?

Is it possible to chemically treat grass after "harvesting" it to make it digestible by humans? I know we can "eat" grass, but we can't break it down in our stomachs. If there is some chemical ...
2
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1answer
3k views

Will adding apple cider vinegar to freshly pressed fruit juice preserve it

Would adding apple cider vinegar to freshly cold pressed fruit juice be able to preserve the fruit juice and extend its shelf life? Would the juice change into vinegar with time?
0
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1answer
196 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 ...
9
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2answers
804 views

Products of Lead(II) nitrate decomposition

It is known, that decomposition of Lead(II) nitrate is one of the ways of generating $\ce{NO2}$ for lab use. I recently did this in order to acquire $\ce{NO2}$ in liquid form (ambient temperature ...

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