For questions relating to the theory, design or performance of chemical experiments, including theoretical structures, expected products, thermal calculations, and empirical analysis.

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What stable arrangements of hydrogen-bonded water exist in the range of 4-20 water molecules?

Water clusters made up of various numbers of water molecules have been described. Are all of these structures theoretical? What experimental evidence supports any of these structures? How does the ...
-1
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0answers
33 views

How to crystallize out reaction mixture from DMF?

Reaction was carried out in DMF, and TLC shows that the reaction has completed. But how to separate reaction mixture i.e. product from DMF?
2
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2answers
570 views

What salts (or other substances) are available for increasing water's boiling point?

Increasing the boiling point of water by adding salts or other compounds would be very useful when working with a water bath while refluxing, because with pure water you cannot reach temperatures over ...
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vote
1answer
54 views

Help with simple DIY procedure to measure diffusion?

While I am not asking the question here, a recent question concerning osmosis at the Bio SE caught my interest. In a nutshell that question was, given isotonic solutions of sugar inside and outside an ...
2
votes
1answer
46 views

Recrystallization of two unknown compounds?

I managed to separate a binary mixture(in solid form) of two unknown substances into two individual solid compounds. For the separation, I used an acid-base extraction with dichloromethane, NaOH, and ...
3
votes
2answers
46 views

Water flow in condenser

How should the water flow in your condenser? From the flask to the top of the condenser, or from the top of the condenser back to the flask? I could imagine both: flask to top will fill the entire ...
3
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0answers
48 views

Rusting of an Iron Nail in Oil and Water

Recently at school, I did some experiments on corrosion. Everything mostly went as expected, but the result in one of the test was quite baffling. This test had an iron nail in water with some of the ...
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0answers
8 views

Synthesizing monodisperse PbS quantum dots

For a research project, I am trying to synthesize lead (II) sulfide quantum dots using the method of Li et al. (http://pubs.rsc.org/en/Content/ArticleLanding/2010/CE/b917833c#!divAbstract). Basically, ...
3
votes
2answers
38 views

Refluxing with tilted condenser

Can you reflux without any problems/dangers with a tilted condenser (e.g. because you don't have enough space in your fumehood)? I would say there isn't a problem, because both the surface area of the ...
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1answer
24 views

What is the fire point of sucrose with an average particle diameter of 60 micrometres?

What is the fire point of sucrose with an average particle diameter of 60 micrometres? I can't seem to find any documentation on this, online.
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0answers
36 views

Reactivity of thiosemicarbazide

How to form Schiffs Base at both the ends of the thiosemicarbazide? Nh2 of hydrazine part reacts easily to form Schiffs base i.e. imine. But NH2 attached to C=S does not. How to do that? One ...
2
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2answers
59 views

Calculating Avogadro's Number

For a school project, I am in a group tasked with calculating Avogadro's Number in multiple manners. Other than the Millikan Oil Drop Experiment, we know of no ways to compute it. A Google search ...
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0answers
8 views

Silica, Alumina and Sodium Hydroxide from Caustic Soda solution

I had a solution containing Silica and Alumina in caustic soda. I need to extract the same from the solution separating Silica, Alumina and sodium hydroxide. How can I do it? Please provide the ...
2
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3answers
83 views

1-octanol in polar but immiscible with water

1-octanol is polar due to the presence of the -OH group but it is immiscible with water. How is it possible?
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2answers
58 views

Preparation of phenylamine/aniline

This is the procedure I carried out in class: Reduction of nitrobenzene by using tin and $HCl$ acid After the completion of the reaction, $NaOH$ added to neutralize excess acid and dissolve any ...
1
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2answers
43 views

Different type of distillations

I know that fractional distillation is used to separate two liquids that are miscible in one another and have close boiling points. However, I am really confused about vacuum distillation and steam ...
0
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2answers
47 views

What is the process involved in performing a mass spectrometry experiment?

I have heard that mass spectrometry is very time consuming: why is this? What is the process involved in performing a mass spectrometry experiment? What steps are the most time consuming?
2
votes
1answer
58 views

What is the difference between the reactivity of Lead subacetate and Lead II acetate undergoing a hydrothermal process?

I am attempting to adapt a hydrothermal method for synthesizing $\ce{PbS}$ nanocrystals to my school that contains a mixture of cationic and anionic surfactants sodium dodecyl sulfate (.05 mmol, SDS) ...
0
votes
1answer
50 views

Explain isotopic uranium/perchloric acid digestion

What is happening in this video? Can you explain this technically as well as in layman's terms? I'll summarize it. I see a technician moving fuming mixtures of presumably uranium and organic ...
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0answers
19 views

To model early fluid flow which types of pumps should be used?

I have I microchannel test rig , I want to push a 150-300 ml/hr from water in my test , I would like to know which pump type i can use ?
2
votes
1answer
175 views

Why is filter paper fluorescent?

Typical filter paper used in chemistry lab (e.g. Whatman #1) exhibits autofluorescence in near UV with excitation maximum at 365 nm and emission maximum at 440 nm. It was reported in literature[1] ...
0
votes
2answers
191 views

Coconut aldehyde Mechanism

How would you draw the mechanism going from 3-nonenoic acid to coconut aldehyde? I know I added Sulfuric acid and sodium carbonate which I was confused how they worked into the mechanism. I am ...
6
votes
2answers
139 views

Questions about Buffer System (Lab)

I will be doing a lab on Hydrogen Phosphate buffer system tomorrow and I have a few questions about the buffer system. I am not sure if my assumptions are correct. (1) What would happen to the rate ...
0
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1answer
49 views

Compare Catalysts in Calorimetry Reaction

I am writing a lab report and need some help understanding something. I have performed a calorimeter experiment and compared the different reactions that were taking place inside it with a ...
5
votes
1answer
64 views

Steam distillation- how it actually works?

To obtain phenylamine after it is formed from the reduction of nitrobenzene with tin, we carried out steam distillation. This is what I learned in class: "During the process,steam is injected ...
2
votes
1answer
159 views

Why can we not use water instead of blank control solution in enzyme catalysis with Peroxidase experiment?

I have to do a lab about enzyme catalysis with Peroxidase in my Chemistry class. We are to use the blank control solution in the experiment. My question is, why can we not use water instead? I did ...
2
votes
2answers
31 views

What's Standardization, and why do it?

Surprisingly, there are very few resources online (outside of obscure lab pages) that explain exactly what standardization is (not even Wikipedia!). The context is the phrase standardize the titrant ...
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1answer
75 views

How alkanes can be prepared by aldehydes and ketones? [closed]

Preparation of alkanes by aldehydes and ketones, its chemical reaction and mechanism.
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votes
2answers
82 views

Getting to use the lab!

Today I finally mustered the courage to go and talk to the director of the labs to politely ask him if I could use the labs out of class hours. Long story short, our lab sessions "are bad" because we ...
4
votes
3answers
70 views

How do I create a concentrated solution of singlet oxygen (in the dark)?

Without appealing to reactions that require photons / light, how do chemists achieve a very high concentration of continually produced, though quite short lived, singlet oxygen in aqueous solution ...
0
votes
2answers
139 views

What does “EM grade” mean

I'm looking at purchase orders and I see purchases for chemicals like the following. Glutaraldehyde, EM Grade, 25% What does the "EM Grade" mean in this text? It says that it's recommended for ...
1
vote
3answers
109 views

Alternatives to Ring Stands

I'm trying to find an alternative to simple ring stands to hold a simple electrochemical cell. The issue is that it is difficult to adjust the height to the right position to within even a couple ...
0
votes
0answers
263 views

How to calculate lattice parameter only using planes and d spacing

I am trying to find lattice parameter of a hexagonal crystal, usually i uses cellcalc for calculating lattice parameter of a crystal struture. In that software it asks only two queries one is details ...
4
votes
0answers
22 views

How to get defect-energy level diagram from PL data

I am reading this article Phys. Chem. Chem. Phys. , 2011, 13, 14902-14905 and seen that the authors have drawn a image of defect level using PL data Can you explain me how this diagram can be drawn ...
7
votes
2answers
6k views

Chemistry behind Gale's Coffee Maker in Breaking Bad

Is there a scientific basis for the coffee making equipment which Gale describes in Breaking Bad? He talks about maintaining the right conditions for bringing out the coffee flavor without degrading ...
3
votes
0answers
585 views

Why are NaCl and NaBr not soluble, whereas NaI is soluble in acetone (in the Finkelstein reaction)?

My book says: Finkelstein reaction is particularly useful for preparing iodoalkanes. The iodoalkanes are obtained by heating chloro or bromoalkanes with a concentrated solution of sodium iodide ...
2
votes
1answer
62 views

Changes in defects in a material due to heat treatment

Currently i am doing some research on optical properties of a oxide material and for that purpose i have done some photoluminescence study on it. Because this is an ongoing research i cant divulge ...
1
vote
1answer
48 views

Why does MgCl2 lower the freezing temperature, and how does it do so?

I am working on a project in my chemistry class, and even though we've already finished the lab, I'm still confused as to why and how $\ce{MgCl2}$ melts ice/ lowers the freezing temperature of water. ...
3
votes
0answers
271 views

Calculation of Atomic weight percentage in AAS

I am currently doing doping studies in a system similar to this ($A_{x}B_{1-x}$) and i have to find atomic weight percentage of $B$ element using atomic absorption spectroscopy(AAS). I have prepared ...
0
votes
1answer
342 views

A volumetric analysis experiment

I completed a titration experiment in a lab. The aim was to find the concentration of the titrant KMnO4 solution by titrating it with a sodium oxalate solution of a known concentration. I first made ...
0
votes
1answer
678 views

How is iron(III) chloride changed from solid to solution?

I'm conducting an experiment using iron(III) chloride in aqueous solution, but am also aware that it's usually a solid. How is iron(III) chloride experimentally converted to a solution? And can you ...
3
votes
1answer
483 views

How would one go about making a cheap freeze spray?

I'm interested in making a liquid freeze spray, for a fun science project. My only experience with this comes in spraying inverting canned air dusters, which spray a -60F mist/liquid (liquid if you ...
1
vote
1answer
703 views

Does a sulfuric acid/nitric acid mixture dissolve PTFE (ie. teflon)?

In our lab, we commonly use a mixture of sulfuric acid and nitric acid to clean borosilicate glassware. I'd like to clean some PTFE pieces in there, too, but not sure if they will dissolve or not. ...
1
vote
1answer
64 views

preparation methods of nicotinoyl glycine

How can we prepare nicotinoyl glycine from nicotinic acid ?Is that possible by reaction between nicotinic acid and glycine?
1
vote
1answer
132 views

$\beta$-mercaptoethanol molarity

I'm writing up a practical and $\beta$-mercaptoethanol was used, with no concentration given. I've found I don't need the BME molarity since I'm giving percentage (v/v) concentration, however I'm ...
3
votes
1answer
106 views

Why is nicotinoyl chloride available as its hydrochloride salt? How can we separate them?

Nicotinoyl chloride is only available as its hydrochloride salt. Why can't nicotinoyl chloride be synthesized in free form? How can we seperate nicotinoyl chloride from its salt form? Can we try any ...
5
votes
2answers
116 views

Removing Ti from Ta Crucible

I'm trying to remove titanium filling from a tantalum crucible for a high-temperature effusion cell. I've managed to get a majority of the material out with tweezers, but some remains and is ...
2
votes
1answer
852 views

Effect of dillution on titration

When we are titrating acid/base using ph meter we add distilled water to immerse the ph electrode. Won't this affect the concentration of the acid/base: I mean isn't this dillution. Won't this ...
2
votes
1answer
593 views

Why is a theoretical titration curve higher than a practical one?

I'm currently in high school and I did two titrations. The first one is a titration of $10.0$mL $0.1$M $\ce{HCl}$ with $x$ mL $\ce{NaOH}$. I obtained the following titration curve: The blue curve ...
3
votes
1answer
177 views

Easy-to-do experiments that clearly show outstanding properties of graphene

By chance, we received some monolayer graphene sheets (20 cm x 20 cm) and mixed coper-graphene wires for free at our university. I would like to prepare some very-easy-to-do experiments for the ...