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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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Chemistry Question [on hold]

What volume (in milliliters) of 0.230 M NaOH should be added to a 0.135 L solution of 0.0150 M glycine hydrochloride (pKa1 = 2.350, pKa2 = 9.778) to adjust the pH to 2.99?
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Acetylsalicylic acid synthesis

In the laboratory, we synthesized acetylsalicylic acid by reacting salicylic acid and acetic anhydride. And during this reaction, a few drops of sulphuric acid were poured in order to catalyse the ...
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1answer
23 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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21 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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Sodium orthosilicate formation [on hold]

1-Can sodium metasilicate (Na2SiO3) react with sodium hydroxide (NaOH) to form sodium orthosilicate (Na4SiO4)? 2-How are orthosilicates (SiO4) made from silicon dioxide (SiO2) or metasilicates (SiO3)...
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Find the density of a solution. also converting solubility of solution (g/kg) to solubility (g/l) [on hold]

Q: Find the density of a solution,whilst converting solubility of solution (g/kg) to solubility (g/l) only having the density of the solute in its solid form is 1.35 g/cm3. I am currently designing a ...
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44 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 ...
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0answers
13 views

Potassium alum powder, hydrogen peroxide, water and baking powder [closed]

I added these three in a bottle (out of nowhere) and it started bubbling. And when it subdued, the liquid was kinda hotter than normal (hydrogen perox) and my finger is kinda rough. So i want to know ...
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Theoretical Experiment — I need help with building a galvanic element with limited materials and chemicals? [closed]

I was given this experiment to do theoretically with some chemicals and materials, and the idea is to maximize the voltage you get from the chemicals that you use in the experiment together with the ...
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0answers
51 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 ...
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28 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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47 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
46 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 ...
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1answer
49 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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20 views

According to Nernst equation, why does voltage drops when temperature raises? [duplicate]

Can someone tell me everything about Nernst equation? Why does voltage drops when temperature raises?
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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 $\...
2
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1answer
69 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
49 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
130 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
50 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
31 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
35 views
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1answer
38 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 ...
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2answers
74 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
37 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. ...
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1answer
33 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{...
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1answer
37 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
30 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
25 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). ...
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16 views

What does Oxidizable matter mean?

BS EN ISO 3696, in page 10, contains a table showing the requirements for different grades of water. This table mentions a term, Oxidizable matter oxygen (O) oxygen content mg/l, max. I know what BOD (...
4
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1answer
47 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 ...
0
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1answer
90 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 ...
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1answer
62 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
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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"....
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2answers
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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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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
31 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
42 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
45 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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146 views
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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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29 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 ...
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1answer
534 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
13 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.
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1answer
34 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 ...
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3answers
47 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
38 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
75 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 ...
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1answer
34 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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40 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+}(...