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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4
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1answer
48 views

Identifying an extra NMR peak in silyl protection reaction

I protected a phenol with the TIPSCl/triethylamine procedure. The product was isolated by column (hexanes/EtOAc) and shows an extra singlet at 1.05 ppm in $\ce{CDCl3}$, integrating to ~10 H. Whatever ...
2
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1answer
94 views

Synthesis of Aspirin, made unknown fluid

When I tried synthesising aspirin, after quenching and cooling it I noticed a translucent, milky, white fluid floating in the solution. The method used was: Salicylic acid (2 ml) was added to ...
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0answers
42 views

What could be causing my cyclic voltammograms to have a sloped scan?

I am running a CV (cyclic voltammogram) in a two compartment bulk electrolysis cell with pH 7 phosphate buffer (0.5 ion concentration) and a napheon membrane separating the two compartments. I'm using ...
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1answer
24 views

Prolonging the exothermic reaction between calcium oxide and water

Is it possible to generate 10-minutes of heat using very small amounts of CaO and water? This is an exothermic reaction. I've done this experiment at home, but it is very short-lived. I'm trying to ...
3
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1answer
44 views

How to capture the gas produced by combusting alcohols

I am burning various alcohols and am attempting to capture the carbon dioxide produced. I could burn the alcohols in a conical flask with a cork on the top, with a tube directing the gas into a gas ...
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50 views

Why does the following “Battery” experiment work?

I did the following experiment: Experimental setup: Two electrodes (one made out of Iron,the other made out of Copper) are put into a (bluish) Copper(ii) sulfate lotion. Then, one connect a ...
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50 views

How to effectively get rid of 2-propanol acetate vapors and smell

I need to get rid of 2-propanol acetate vapors and its smell and need some chemistry help. Some possibilities I came up with: soap and water to rinse surfaces because soap might help increase its ...
4
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0answers
63 views

An unknown glassware piece from our cupboard

We have multiple of these. It is a small glass funnel with splits into 3 spouts from it. Now, we are thinking it might be similar to a cow receiver, however, I have never seen one this small or ...
4
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0answers
32 views

Unknown possibly handmade glassware- description in information below

Okay, Another random item from the cupboard (unknown users or discipline of life sciences unknown) could be anything up to 40 years old.... This appears to be a 2 neck quickfit adapter (B19 and B14) ...
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0answers
54 views

Unknown glassware please help, vshaped with a small bulb on one side, hollow but narrow to both sides!

Looking to try an identify some glassware we have found in a cupboard. This is just the start of it... 1 item here, v-shaped, small bulb but hollow, narrow entrance and exit...
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1answer
54 views

How can I check the sodium content of food?

What is an easy (i.e., home project) way to measure sodium in food? For example, the nutritional label of a tahini brand that I often consume shows very little sodium (around 10mg/100g). I suspect ...
0
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1answer
50 views

Uncertainties Calculation

Recently I did an experiment on isolating casein and now that I am processing the results, I feel my method of uncertainty calculation is not feasible. The casein was isolated 3 times and the results ...
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1answer
1k views

Using a gas stove instead of Bunsen burner for a flame test?

In all chemistry labs we use the Bunsen burner. What's the difference between it and a good old gas stove used in home? Can the stove also be used to get positive flame tests for some cations (like $\...
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1answer
94 views

Why doesn't N2O give a positive brown ring test?

A common nitrate test, known as the brown ring test can be performed by adding iron(II) sulfate to a solution of a nitrate, then slowly adding concentrated sulfuric acid such that the acid forms a ...
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1answer
51 views

Can I determine purity of isopropanol with a hydrometer?

Assuming I start with a known 99.8% purity of isopropanol, after recovery with a distillation apparatus, could I use a hydrometer to test for water content? If so, is there a special one I should use?
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2answers
144 views

LiOH hydrolysis of methyl 2,2-dimethoxyacetate not giving product?

I am forming 2,2-dimethoxyacetic acid from its methyl ester, and below is the experimental protocol I am following (from Tetrahedron 2016, 72 (3), 420–430): 2,2-Dimethoxy Acetic Acid Formation ...
6
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2answers
66 views

Removing sodium borate for the test proving thiocyanate ions

I've just learned that when carrying out the identification test for thiocyanate ions borax can induce a false positive and therefore needs to be removed. I couldn't find the answer on google so I'm ...
1
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1answer
34 views

Could this solution be resolved by titration?

I have a mixture of $\ce{NH_4NO_3}$ and $\ce{NH_3}$ at $\ce{pH}$ of about 13. It is possible to determine the concentration of both on them by acid-base titration? I was told it's possible, and that ...
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1answer
39 views
0
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1answer
44 views

Gas evolution in reaction between zinc and HCl

So I was doing a chemistry lab for school, and we were analyzing how the concentration of a solution affects the rate of a reaction. In order to do this, we used the inverse burette method for the ...
3
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2answers
79 views

Can a reactor be operated at both reflux and above atmospheric pressure?

I'm not a chemist by trade so my experience in the lab has probably not been as in-depth as most of you. I've been tasked with investigating a proposed reaction in which an organic mixture (mostly ...
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2answers
57 views

Citric acid and ammonium nitrate

Soil based question. I have soil with to much Ammonium Nitrate in it. I am wondering if I use citric acid and water mixed will that flush out the extra Ammonium Nitrate that has built up in the soil. ...
0
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1answer
61 views

Observations when mixing potassium Triiodide and Sodium thiosulfate [closed]

I have a reaction equation, it's all balanced but I don't understand what the physical change is. It is as follows: $$\ce{2Na2S2O3 + KI3 \to 2Na2S4O6 + 2NaI + KI}$$ It was used to prove if $\ce{...
2
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1answer
49 views

Does hydrochloric acid change in concentration over time?

I have new bottles of 1 N hydrochloric acid from Fisher. The acid comes standardized from the company: Standardized at 25 °C to pH 8.2 against sodium hydroxide that has been standardized against ...
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0answers
37 views

Can I make an ionic liquid from glycerin and zinc sulfate?

Can I make an ionic liquid (dissolved salt without water) by combining zinc sulfate and glycerin? I've been using 1 M $\ce{ZnSO4}$ as my electrolyte in supercapacitor study. Works very well up to ...
2
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1answer
28 views

What considerations are made in determining whether to use a sand bath or oil bath?

As suggested by the title, I am curious as to what would make, for instance, a sand bath better suited to a specific heating application/context as opposed to an oil bath (and vice versa). ...
4
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1answer
60 views

Role of NaI in Formation of Silyl Enol Ethers using Chloro(trimethyl)silane

I am forming silyl enol ethers using Chloro(trimethyl)silane (TMSCl), and below is an experimental protocol I am following Silyl Enol Ether Synthesis In an oven-dried 100 mL three-necked ...
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1answer
101 views

Does dilithium exist? [duplicate]

Lithium has two electrons in $\mathrm{1s}$, filling the first energy level; and one valence electron in $\mathrm{2s}$. Could two $\ce{Li}$ atoms form a bond to create $\ce{Li2}$; like $\ce{O2}$ or $\...
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1answer
44 views

What does it mean by 'the residue was taken up in solvent' in synthesis protocol?

The below is a synthetic protocol I need to perform: N-trifluoro acetoxy succinimide Synthesis Trifluoroacetic acid anhydride was added to N-hydroxysuccinimide at 0 °C. The reaction was ...
1
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1answer
68 views

How do I identify the compound(s) that formed from a failed synthesis of another compound?

A general answer to the question is great, but specified to my problem is very much welcomed. My team had a lab project — to synthesize chrome alum crystals. We first dissolved $0.3 \, \rm g$ of ...
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2answers
98 views

Scientific Reason for Salt Solution Gaining Volume

A little background to this question: my mom placed a glass with salt and enough water to just cover the salt in a room to "absorb negative energy" out of the room at her office. It obviously "worked"....
21
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2answers
3k views

Storing hydrofluoric acid before the invention of plastics

The first person to synthesize hydrofluoric acid in large quantities was Carl Wilhelm Scheele in 1771. This acid is known for its ability to corrode glass and metals. What materials were the ...
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0answers
18 views

How to decolorize blue fabric whitener?

After adding 4 drops of fabric whitener in water, what should I add to decolorize the solution and turn it clear like water?
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1answer
38 views

Does there exist a dye that will primarily bind with water in a water/oil emulsion?

I'm wondering if there exists a type of dye that will bind primarily with water when introduced to a water/oil emulsion. That way if the water is centrifuged to the bottom of the vial, it will be dyed ...
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0answers
56 views

method to certify the number of chiral carbons in fischer and haworth projection of glucose

While reading some notes about Glucose and its various projections: Fischer Projection: 4 chiral centres Haworth Projection: 5 chiral centres My doubt is that is there any (specific) method (...
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3answers
59 views

What is the proper laboratory technique to place a solid in a beaker that will be weighed?

I was doing a lab at school yesterday which involved transferring a precise amount of solid reagent into a beaker. The way my professor told me to do it was to tap the reagent container so that the ...
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0answers
215 views

Role of pH in azo C-coupling reaction, continued

In the question, "What is the role of pH in azo coupling reaction of diazonium with phenol and aniline?" asked by @DhrubaBanerjee and answered by @Klaus-DieterWarzecha, I find several ends untied. I ...
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0answers
62 views

Dissolving copper in nitric acid and heating it

A sample of copper metal is dissolved in 6 M nitric acid contained in a round bottom flask. This reaction yields a blue solution and emits a colorless gas. The water is evaporated form the blue ...
7
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1answer
546 views

What is the purpose of trimming the bottom corners of TLC plates?

During my chemistry lab course, I was told by my instructor to make 2 small cuts on the bottom corners of the TLC (Thin-Layer Chromatography) plate. Does this make the solvent rise uniformly on the ...
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0answers
17 views

How can I dissolve photography film?

I am looking to completely dissolve negative film strips. Acetone was my first try and did not work. If anyone knows/ or has any ideas i would be so greatful.
0
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1answer
37 views

Reference Books on Electrolysis and Chemical Titration process [closed]

I'm in a General Chemistry course in college. We have laboratory, and then we are supposed to make a report on what we did, etc. I'm not entirely sure what the last laboratory was about, but it was ...
2
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3answers
86 views

Changing the order of the reaction with change in concentration

The reaction $$\ce{2 A + B + C -> D + 2 E}$$ is found to follow the rate law as $$r = k[\ce{A}][\ce{B}]^2[\ce{C}]^0$$ If the concentration of $\ce{A}$, $\ce{B}$ and $\ce{C}$ increases two times ...
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1answer
45 views

Simplest distillation setup

I would like to start learning practical chemistry. I have not done chemistry before and am seeking help assembling a simple distillation setup. I do not want to use the cold water tubes etc for the ...
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2answers
85 views

How to keep a flask submerged in water?

I am trying to keep a 1000 ml Erlenmeyer flask submerged in a deep cooking pot filled with water. I tried tying the flask to a metal plate, but it was too light unfortunately. Is there a purpose ...
0
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1answer
57 views

Heat of hydrogenation

If benzene is more stable than cyclohexane then why is the heat of hydrogenation of benzene negative, ie heat is released during the formation of cyclohexane from benzene ?
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70 views

Does increasing the concentration of the anode electrolyte in a galvanic cell increase or decrease the voltage produced

Im in kind of a pickle here. I am using nernst equations to calculate the theoretical voltage produced for different concentrations of $\ce{Al(NO3)3}$. Reaction: $$\ce{2Al(s) + 3Pb^{2+}(aq)⟶2Al^{3+}(...
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1answer
51 views

Understanding the setup of a chemistry lab about redox

In chemistry lab we were looking at oxidation and reduction reactions. To determine the relative activity of several metals we observed reactions between the metals and aqueous solutions of dissolved ...
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0answers
23 views

how does mass of carbon 12 is like this? [duplicate]

1u is defined as per carbon 12 so 1 atom of c have 6 neutrons and 6 protons both having mass more than 1u (Google)so total mass of carbon 12 is more then 12u (also there would be some mass of ...
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0answers
37 views

How to confirm a powder is Sodium Hydroxide?

Long-story-short, my mother found a bag of white powder with some soap making supplies. We're about 90% sure it's powdered lye, but I thought it would be fun to confirm this somehow. Is there a way ...
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0answers
27 views

Steps of crystallization

An excess of copper(II) oxide is added to dilute sulfuric acid to make crystals of hydrated copper(II) sulfate. The processes listed may be used to obtain crystals of hydrated copper(II) sulfate. ...