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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Which recorded Volume of sodium thiosulphate do i need to use to calculate the amount of caffeine from iodometric back titration

Short overview of the experiment: I am titrating iodine with caffeine against thiosulphate to determine the amount of caffeine. Therefore, I add iodine with hydrochlorid acid and the caffeine into a ...
Saskia's user avatar
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-1 votes
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15 views

what is the role of extra amine in my system at room temperature?

I have methoxysilane, silanol, epoxy resin, and aminosilane in one system, and amine groups are more than the required amount to react with epoxy groups, what is the role of extra amine in this ...
Ghasedak's user avatar
-1 votes
0 answers
24 views

how would moisture content affect Melting Point measurement (capliary tube apparatus)

I have an unknown organic solid from which I need to take a melting point. I prepare a capillary tube with the customary 2-3mm of packed powder sample. Say the sample was dried, but had been ...
some bits flipped's user avatar
1 vote
0 answers
40 views

What precipitate is formed when a copper coin is dissolved in concentrated nitric acid?

The method being used. I am currently carrying out a school project where I am determining the copper content of 1p coins. The coins used are British 1 pence coins dated before 1992 as after this year ...
Katie's user avatar
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-1 votes
1 answer
32 views

What could be used to thicken Ferric Chloride solution?

I'm curious if it's possible to thicken Ferric Chloride so I can control it more on a less than horizontal surface ?
DevChemStudent's user avatar
2 votes
0 answers
39 views

Calculate percent composition from XPS?

I have an XPS graph and was wondering how to calculate percent composition. I do have the percent compositions that were determined from the graph, but I don't know how they were found. For reference, ...
lzzard's user avatar
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1 vote
0 answers
49 views

Why is my result for the oxygen content in CuO so high?

Recently, I conducted a practical in which I was heating a sample of copper(II) oxide reacting with methane to find the empirical formula of the oxide by removing oxygen: $$ \ce{4CuO(s) + CH4 -> ...
TheMathsPerson's user avatar
0 votes
1 answer
79 views

Testing whether an unknown powder is wheat gluten (at home)?

Last week, I ordered wheat gluten to make seitan. I received some powder and attempted a recipe, which mixes 100g of water with 100g of gluten to form a sticky dough. However in my case, I only got a ...
Alduno's user avatar
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1 vote
2 answers
48 views

Oxidation of Isopropanol by Permanganate in Basic Solution

so I've been designing an experiment where I will explore the effect of isopropanol concentration on the colour change of a solution containing permanganate, isopropanol, and NaOH. I know that the ...
Brian Yu's user avatar
2 votes
0 answers
35 views

How can I refine my method of determining iron content in spinach?

I have begun a chemistry experiment that attempts to determine how iron content in spinach is affected by the length of time it is cooked. Through research, I learned that iron content is often ...
beebs's user avatar
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7 votes
2 answers
562 views

Question about the differences of white and grey NaH properties

We are having some problems with the next reaction in our lab. As you can see, is the sulfonylation of an indole in which we use NaH (60% dispersion in mineral oil) as a base. This reaction goes with ...
Alicia's user avatar
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0 answers
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Feasibility of Linking a Voltaic Cell to an Electrochemical Cell

I recently conducted an electrochemistry experiment in which I connected a voltaic cell to an electrolytic cell. The voltaic cell contained copper (wire) and aluminium (foil) electrodes and when ...
Choze's user avatar
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-2 votes
0 answers
40 views

Is there something like semi heavy water DHO [duplicate]

Just curious to know that something asymmetrical like this exists or not!!
VATSAL's user avatar
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0 answers
58 views

How to remove hexane from nBuLi

As described in a paper, the authors removed the hexane from the nBuLi solution "under reduced pressure". I was wondering if anyone had any experience on how to proceed safely with this ...
The Red Man Jolan Bonelli's user avatar
0 votes
0 answers
38 views

Some particles are observed inside the wall of glass vial

Recently, when I use glass vial, some particles are observed inside the wall. These particles are so small and transparent or maybe white-colored, so it is hard to observe during ordinary usage. But ...
Krang Lee's user avatar
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1 answer
65 views

Volumetric flow rate ratio calculation

I'm using two tanks of nitrogen and oxygen and mixing them in different ratios to change the oxygen partial pressure in the system. System is opened to the atmosphere through the venting pipe which ...
Dario Mirić's user avatar
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0 answers
67 views

What determines the pressure in the system when the gas tanks are opened?

I have two gas tanks of nitrogen and oxygen. Mixture of gases is created at specified composition and used in the system of interest. Let's say I want to create an atmospheric conditions in my system, ...
Dario Mirić's user avatar
1 vote
1 answer
60 views

Could I expect any adverse reactions with this ink mix?

Our newest R&D project for a permanent, outdoor ink includes: $\pu{25 g}$ of solvent blue 70. $\pu{25 g}$ of nigrosene. $\pu{??? g}$ of silver nitrate in a denatured alcohol base. Several "...
DevChemStudent's user avatar
0 votes
1 answer
106 views

Is this evidence that solubility of sodium bicarbonate<sodium carbonate?

Someone introduced $\ce{CO2}$ into saturated $\ce{Na2CO3}$ solution, and observed that white precipitate is produced. He therefore claims that $\ce{NaHCO3}$ has less solubility than $\ce{Na2CO3}$. His ...
youthdoo's user avatar
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0 answers
28 views

Does manganese dioxide disperse differently in bases than in water?

As part of a project in uni I've been given a task in my chemistry laboratory to synthesise manganese dioxide powders. I prepared a precipitate of it by reacting manganese chloride with sodium ...
A. Sreeram's user avatar
1 vote
0 answers
28 views

Surface treatment and current density: electrodeposition of Cd and Ag

I'm currently working on a cadmium and silver electrodeposition project. Let me explain: I'm doing electrolytic surface treatment on low-alloy steels as well as stainless steels. At present, we have ...
Soporelle's user avatar
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0 answers
29 views

Is it possible to create a solid from PVDF solution?

I am working on a project where I am attempting to line an aluminium tube with PVDF. The finished wall thickness is required to be 4mm thick. I have investigated such processes as injection moulding ...
PERRY COOPER's user avatar
-4 votes
1 answer
64 views

The log K value for Cr-EDTA complex is 23, still Cr(III) cannot be titrated directly [closed]

It's related to stability constants. I don't get the question and where is it taking and wanting to answer.
Akshita's user avatar
-1 votes
1 answer
56 views

What precipitate forms when adding aqueous sodium sulfate solution to an unknown white solid?

I don't understand why there aren't two solutions to the following problem: You are presented with a white solid and told that due to careless labeling it is not clear if the substance is barium ...
Spi-Phi Quotes's user avatar
1 vote
1 answer
192 views

Assignment of NMR peaks of polystyrene

I’m having trouble identifying the peak around 3,75 ppm in the 1H-NMR spectrum of polystyrene measured at 400 Hz in CDCl3. Could someone please provide their perspective on it? I see it appear in a ...
yumocci's user avatar
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3 votes
1 answer
85 views

Schlenk line simultaneously opening vacuum and gas

I’ve been working in the lab for some time now, but I’ve found conflicting information when asking this question, so maybe you know the answer. When working in a Schlenk line with double oblique ...
Mäßige's user avatar
2 votes
2 answers
174 views

Should I remove inhibitor from methyl acrylate?

I need to run multiple aza-Michael additions of methyl acrylate with various amines (dimethylamine, benzylamine, phenylethylamine, aniline, etc.) in order to get the bis-ester. I was wondering if the ...
Matt's user avatar
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4 votes
0 answers
43 views

Largest molecules verified in a Miller Urey experiment

What are the largest molecules confirmed with confidence in a Miller Urey experiment? I know the experiment can create amino acids (which are mostly <250Da) and nucleotides (which are mostly <...
fireworksparkle's user avatar
1 vote
0 answers
20 views

visualization problem of dilution of enthalpy $\Delta_{dil} H$ data with different initial concentrations

description I have a question about the $m_f$ vs. $\Delta_{\text{dil}} H$ plot in some experimental studies. For example, the dilution-of-enthalpy data at 300 °C with two initial concetration ($m_i$) ...
acaduck's user avatar
  • 73
0 votes
0 answers
41 views

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.
Chemistry guy's user avatar
7 votes
1 answer
739 views

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 ...
rmza7's user avatar
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-2 votes
1 answer
73 views

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 ...
Clinfosfito's user avatar
-1 votes
1 answer
242 views

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 ...
Saif's user avatar
  • 35
2 votes
2 answers
216 views

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 ...
Harikrishnan M's user avatar
1 vote
0 answers
32 views

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 ...
DocManIM's user avatar
-3 votes
1 answer
179 views

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 ...
SHADOW LEGEND's user avatar
-1 votes
1 answer
101 views

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 ...
Tommy's user avatar
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2 votes
1 answer
97 views

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 ...
xoux's user avatar
  • 134
2 votes
0 answers
52 views

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(...
Thomas Pluck's user avatar
0 votes
1 answer
42 views

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 ...
Stephanie's user avatar
1 vote
0 answers
95 views

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 ...
user139437's user avatar
1 vote
1 answer
230 views

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 ...
user139281's user avatar
2 votes
3 answers
155 views

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 ...
user avatar
3 votes
1 answer
334 views

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 ...
Fractal's user avatar
  • 203
-3 votes
1 answer
115 views

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 ...
CarbonatNatria's user avatar
-2 votes
1 answer
106 views

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?
Hope's user avatar
  • 115
1 vote
1 answer
33 views

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 ...
kl314's user avatar
  • 19
-2 votes
3 answers
313 views

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,...
Alexei Rothschild's user avatar
2 votes
2 answers
63 views

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 ...
Shan's user avatar
  • 21
2 votes
1 answer
226 views

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'...
Jack's user avatar
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