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 ...

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2
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1answer
70 views

How Many mL of 1.0M HCl Would be Required to Completely Decompose Sucrose into Glucose and Fructose?

I am currently conducting an experiment into the glucose content of certain sports drinks. However, I have hit a roadblock. A majority of the drinks that I intend to test contain sucrose. I am ...
8
votes
1answer
56 views

Organic solutions that corrode metals

Most of the common organic solvents are regarded as noncorrosive, but stainless steel can be attacked by formic, acetic, and propanoic acids. Corrosion of stainless steel by organic solvent ...
2
votes
0answers
14 views

What causes the difference in heat energy released by combustion for the Butanol isomers?

I am currently working on an investigation where I am burning isomers of butanol to test for the heat of combustion values to see which fuel is most efficient. The fuels I am testing are 1-butanol, ...
5
votes
1answer
30 views

NaOH Normality Slowly Changing

Our lab uses a sodium hydroxide solution of a (theoretically) known normality (0.8000 - 1.0000) to titrate product samples for quality control. However, we suspect that the normality of the ...
0
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0answers
22 views

Tell the cases in which stirring causes delay instead of increasing the reaction rate? [closed]

Tell the cases in which stirring causes delay instead of increasing the reaction rate? Assume both the reactants in liquid or gas state.
5
votes
0answers
31 views

Belousov-Zhabotinsky reaction: questions about rate determining step, k and activation energy

In one of our lab courses, we performed a variation of the BZ reaction, the experimental procedure is outlined below: Experimental Procedure 10 mL of 3.0 M $\ce{H2SO4}$ was added to test tube T1. ...
4
votes
1answer
35 views

How are the chemical reactions of the table of standard reduction potentials experimentally determined?

My background: I've read several books and articles on electrochemistry and even do photoelectrochemical research in a lab, so I'm somewhat familiar with the concepts and techniques. In texts on ...
4
votes
1answer
64 views

Why can't I reproduce this photolytic reaction?

I was so intrigued by the reported observation that sunlight precipitates the iron from $\cf{K4Fe(CN)6}$ (originally attributed to Matuschek, 1901) that I wanted to see it myself. I put a saturated ...
3
votes
1answer
60 views

Titration of reducing sugars on honey

So I'm trying to figure out how to titrate the reducing sugars on honey without generating iodine. The reaction so far I think I could do is do a Fehling reaction with $\ce{Cu}^{2+}$and then ...
3
votes
1answer
258 views

Why are the mass ratios of O to KClO3 and O2 to KClO3 the same?

I just did a lab that involved heating KClO3 (with MnO2 as a catalyst) to decompose it into KCl and oxygen gas. That part is easy. What's throwing me is the % yield calculations. The theoretical ...
-1
votes
1answer
50 views

How to calculate the requirements for breaking a bond?

Once you have calculated the bond energy (enthalpy) required to break a bond, say it’s a $\ce{C-OH}$ bond, how do you then calculate or determine the temperature in °C and time it would take at that ...
2
votes
1answer
70 views

Making carbon monoxide gas from formic acid and sulphuric acid?

Can I create carbon monoxide gas by just mixing formic acid and sulphuric acid together. Or do they have to be heated?
1
vote
2answers
46 views

Chloroform-acid wash

If I wash chloroform (stabilized with amylene) with sulphuric acid in a separating funnel, where will the chloroform be found (top or bottom)? I think the chloroform will be at the bottom, because it ...
0
votes
2answers
62 views

How can I convert the number of particles per liter to gram per liter

How can I convert the number of particles per liter to gram per liter? I know the size of these particle and so, I calculated the volume and then by the density I calculate the mass. After that I ...
5
votes
1answer
356 views

Best Fuel for Potato Gun

I have been using deodorant to propel potatoes (potato gun :D), but I want to switch over to pure butane. However, in order to do this safely I have to know how much butane is typically in deodorant ...
11
votes
1answer
122 views

Byproducts in Indigo Synthesis?

I have been messing around with making Indigo dye while waiting for bacteria to grow. I have been following the Baeyer-Drewson method. Basically, you mix nitrobenzaldehyde with an acetone water mix ...
0
votes
0answers
22 views

How can I use sunlight to heat a RBF and reflux a reaction?

This may seem like a off topic question but I really need help on it. I am currently working on a polymerization reaction in which I'm breaking down plastic polymers into smaller molecules. However, ...
2
votes
0answers
7 views

Limits on contaminant size in filtration for extraction, and standard alternatives?

Following up on How to perform solvent extraction of a solid I realized that I haven't quantified the size of the contaminants. I know they aren't soluble in acetone and the target is, but I don't ...
11
votes
2answers
428 views

Are PTFE stir bars resistant to all lab solvents?

It seems like glass-coated stir bars are a specialty item. Standard stir bars are coated in PTFE. Is PTFE resistant to all typical lab solvents? Or is there a reference to check to ensure it is ...
2
votes
1answer
58 views

How do I find the empirical formula for Co(C2O4)*H2O with mass of Oxalate and Oxide Product?

I have the formula $\ce{Co(C2O4)*H2O}$ in a reaction that forms cobalt oxide $\ce{Co3O4}$ – My data here says that my oxalate hydrate weighed 0.3283 g and my product oxide weighed 0.1158 g which I ...
0
votes
0answers
21 views

How do I set my vacuum regulator for filtration?

I know about what pressure the gauge reads on my hand pump when I am doing filtration at max vacuum (greatest vacuum that does not break the filter) which is about 20 inches $\ce{Hg}$ vacuum. How do I ...
1
vote
1answer
32 views

What is CIF (a PCB developer) and what does it do?

I made a PCB (printed circuit board) for the first time, and the process included covering the board with the shape we want, exposing the board to UV light and then putting it in a developer which ...
3
votes
1answer
35 views

Alcohol in the bloodstream modeled by differential equations

Does anyone know any good references which use partial differential equations to model the alcohol concentration in the bloodstream? I'm a mathematician, so I'm searching for a rigorous mathematical ...
0
votes
1answer
49 views

Cleaning silver - which method is better? [duplicate]

What is the advantage of this approach over polishing the silver with an abrasive? "Silver tarnish is an outer coating of silver sulfide, $\ce{Ag2S}$, formed when silver reacts with trace quantities ...
3
votes
0answers
31 views

Calculating K Value of a Clock Reaction

Uncertainty Not Included Some Units Not Included R2 value calculated from Header (Concentration, 1 over Concentration and LN Concentration) vs Time Column of ...
1
vote
1answer
38 views

Help determining the amount of hexavalent chromium to use?

My friend is working on her Masters and needed my help confirming some math. The literature she is referencing says to expose her fish to $3~\mathrm{mg~L^{-1}}$ of hexavalent chromium. We at our ...
2
votes
1answer
37 views

How to perform solvent extraction of a solid

Suppose I have a solid compound from which I want to extract a target chemical I know is soluble in acetone. So I crush and mix the compound in acetone, dissolving the target and suspending the ...
3
votes
1answer
36 views

Distillation Heating Mantle Setup

In my lab courses, we were taught to use textbooks off the shelf as elevating props to adjust the heights of heating mantles to the right height during distillations, but I was wondering if there was ...
3
votes
2answers
84 views

How do I setup the electrodes for cyclic voltammetry on a capacitor made on dry copper sheets?

I'm trying to measure capacitance of a cell I'm creating. It's composed of two copper-sheets with nano-material coated on one side, sandwiched with a membrane and wetted with $\ce{KOH}$. All of the ...
6
votes
1answer
47 views

Does phosphoric acid remove stainless steel electropolished layer?

Electropolished stainless steel has a high corrosion resistance due to the oxide film that is created during electropolishing. The film mainly consist of chromium(III) oxide. Phosphoric acid is ...
5
votes
0answers
35 views

Can I make Ferrofluid without evaporating Ammonium?

I want to make ferrofluid, which is ferromagnetic particles suspended in a carrier fluid. Three methods I have seen involve using magnetic ink (for MICR codes), cassette tapes, or ferric chloride as ...
6
votes
0answers
52 views

How Do I Identify What Impurities Are in My Product?

I am writing a lab report for Organic Chemistry about a multi-step synthesis that we conducted. While our product has the proper melting point, its IR spectrum has peaks not present in the respective ...
6
votes
2answers
114 views

Proper use of vacuum pump during vacuum distillation

I am preparing to do a vacuum distillation and am unsure exactly how to manage the vacuum. The vacuum pump I have is a two-stage rotary vane pump which is capable of 250 microns or lower. It has a ...
6
votes
1answer
78 views

H2SO4 with ethanoic acid reaction?

Earlier today I was preparing an ester (propyl ethanoate) and I noticed that instead of putting the propanol, ethanoic acid and $\ce{H2SO4}$ in the test tube and warming it (taking time and external ...
5
votes
0answers
29 views

Reduction of vanadyl ion

I want to reduce vanadyl to vanadium (III), can somebody please suggest some appropriate methods for it? I am trying to make a redox flow battery for a project but I have only vanadyl sulfate.
1
vote
0answers
20 views

Looking for a Chemistry Demo Resource Group

I'm looking for some kind of email list, forum, or group that discusses chemistry demonstrations. I'm working on an improvement to a demo that's been used for a few decades at my institution and I'm ...
6
votes
1answer
75 views

Why must NaOH be kept dry during storage?

Why should the Erlenmeyer flask used to store $\ce{NaOH}$ be dry? Why should it be kept covered at all times?
10
votes
1answer
150 views

Why do some solvents bubble more than others when boiling?

This question about boiling milk reminded me of my everyday lab work at the rotavap: Some solvents and solutes are feared for the intense bubbling they create while the solution is boiling — be it at ...
5
votes
1answer
128 views

How to get a precise reading from pipette?

While doing titrations, we are instructed to use pipette and they demonstrated how to use a pipette. But still after all this, we face difficulties of how to take precise reading from pipette. ...
5
votes
1answer
63 views

how to destroy excess iodomethane in reaction mixture?

I have used iodomethane to make a phenolic $\ce{OH}$ group to $\ce{OMe}$ group in Aq+Methanol medium. I have added water to precipitate the product of mine and will evaporate the solvents but I cant ...
16
votes
1answer
644 views

How can an inexperienced chemist determine the chemical structure of a molecule?

I'm a fairly inexperienced, but nonetheless interested chemist, currently planning a small project for the coming summer: I want to isolate an unknown chemical from a plant and determine it's chemical ...
0
votes
0answers
23 views

Qualitative Analysis of Anions

From the image above, if you all could take a loot at step 1a. It makes no sense to me. I do not understand why adding $\ce{CH3COOH}$ has any effect on the solution whatsoever. What is the point of ...
-1
votes
1answer
20 views

Cathode rays produce heat when they fall on a matter

I have studied this many times in my Chemistry F.Sc-1 book that cathode rays produce heat when they fall on a matter but this thing is beyond my comprehension that how they produce heat?
4
votes
0answers
23 views

Linear PEI Solution Making

I'm making a solution with linear poly(ethyleneimine) $\ce{[CH2CH2NH]_{n}}$. The bottle indicates that the substance is hygroscopic and must be dealt with under inert gas. Is this really necessary? ...
10
votes
2answers
99 views

Dissolving metal reductions

Could reduction of an organic compound by reacting it with sodium dissolved in $\ce{NH3}$ still proceed if a metal such as aluminium were used instead of sodium? I'm not sure about the aluminium amine ...
5
votes
1answer
122 views

Purification of Ethanol

In Vogel's organic book, they have mentioned that in the Lund and Bjerrum method of purification of ethanol, magnesium is added, which forms ethanolate. But they said to activate the magnesium first ...
2
votes
1answer
76 views

Separate precious metals from catalytic converter

I am looking to separate the small quantities of platinum and palladium in a catalytic converter. However since these are very inert metals I am unsure how to proceed about doing so. Melting the ...
3
votes
0answers
40 views

Choosing the instrumental techniques for chemical analysis [closed]

Since every technique has its goods and its bads characteristics, it's a bit hard for me to choose between them to determine specific elements, methods such as UV-VIS spectroscopy, IR spectroscopy, ...
1
vote
0answers
35 views

How photoluminescence (PL) spectroscopy works

Photoluminescence (PL) spectroscopy is used to find the energy levels in a compound but how does PL spectroscopy works? After exciting a material with a particular wavelength whether PL machine looks ...
2
votes
2answers
342 views

How common are automated pipetting systems

It's clear that automated pipetting is faster than doing it manually, but how common is it for a lab to have an automated pipetting system, and what usually are the circumstances that a lab have ...