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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5
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1answer
56 views

How to prevent dripping when using a Pasteur pipette with solvents like diethyl ether?

I'm trying to use a Pasteur pipette for pipetting diethyl ether and regardless of the angle I hold the pipette at, the diethyl ether will automatically start dispensing itself (I am unsure of what ...
2
votes
1answer
42 views

Gel electrophoresis separates proteins on the basis of what property?

In SDS-PAGE for separation of proteins, SDS is an ionic detergent that coats the unfolded protein to mask its native charge and give at a uniform charge to length ratio. Since the length of the ...
-1
votes
0answers
12 views

Dilution Factor [on hold]

A laboratory has copper II sulfate solution S0 of molar concentration C0=1.0mol/L. The lab must prepare by diluting the solution S0, a solution S1 of volume V1=250mL and of molar concentration C1=0....
1
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2answers
23 views

How does impurity of distilled water vary with time in air?

If I place distilled water in a glass beaker, how long is it expected to stay distilled? What are the causes of it's impurity through air or other sources?
1
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0answers
17 views

Does the synthesis method used to make graphene oxide composites matter?

I'm doing a research project to test the photothermal conversion performance of graphene oxide composite materials. We're using a number of different metals and metal oxides ($\ce{Au}$, $\ce{Ag}$, $\...
1
vote
1answer
23 views

Evaporate propylene glycol

I tried to make a cannabis infused e-liquid. I made a tincture with marijuana and vegetable glycerin, but it became to thick so a mixed in more propylene glycol than I'd originally planned. Now the e-...
1
vote
2answers
33 views

Is there a way to counteract the problems with weighing hot objects?

I am currently performing an experiment in which it would be greatly beneficial to be able to accurately measure the mass of a hot object without waiting for it to cool. The current plan is simply to ...
0
votes
0answers
12 views

Easieast method of air oxidation of octan-2-one to two carboxylic acid? [closed]

im trying to find simplest method to convert methyl hexyl ketone to two carboxylic acid with out using catalyst as i need to apply in industry scale. can anybody help me in this regard
0
votes
0answers
14 views

Calculation of precise Methane concentration in a closed vessel (incubation bottle) (Gas chromatography)

I'm having some difficulties interpreting results from one of my experiments and more precisely, I'm lost in conversion between units, taking into accounts dilution factors etc. Basically I'm running ...
-1
votes
0answers
23 views

Empirical formula of a hydrate

I am trying to determine my unknown salt by looking at the percent of water. I'm thinking that I maybe did something wrong in the experiment but I ran two trials. Trial 1 mass hydrate in grams is 4....
4
votes
1answer
77 views

How much lactose is there in milk (mechanism)?

Iodometric titration is sometimes used to find out how much lactose there is in milk. The overall oxidation reaction is written as follows. $$\ce{C12H22O11 + I2 + 3NaOH ->[\ce{CuSO4}]C12H21O12Na + ...
0
votes
0answers
33 views

If pure silicon and water are combined and then subjected to radiolysis from Gamma radiation, what will the product be

I asked this and I was told that The radiation would probably rip bonds apart indiscriminately, making hydroxyl radicals, hydrogen atoms and a large concentration of crystal defects in the silicon....
1
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0answers
23 views

Let's create a masterlist for generic sources of errors and suggestions to improve them [closed]

This would be very helpful for the writing of lab reports, etc. The correct answer will be the one that has the most number of useful sources of error as determined by number of votes. To get the ...
5
votes
2answers
58 views

Percent difference: What to place on the denominator?

I'm genuinely confused on what to put on the denominator for the formula $$\%~\mathrm{difference} = \mathrm{\left|theoretical~-~experimental\right|\over theoretical}$$ or some other similar formula ...
3
votes
1answer
57 views

Concentration of NaOH to dissolve glass

I am doing a physics experiment in which it is required to etch the outermost glass layer from a coverslip (regular lab apparatus). What concentration of NaOH should be dissolved in water, and how ...
1
vote
2answers
45 views

Drying solvents while taking care of purity

I need to dry some solvents like $\text{MeOH, EtOH, and DMSO} $ and I have to take care of purity of the solvents. These solvents are HPLC grade. I am interested in freezing point and boiling point ...
3
votes
1answer
232 views

How are van der Waals parameters determined experimentally?

If the ideal gas law $PV=nRT$ is not enough, as a second approximation the van der Waals equation $$\left(P+a\frac{n^2}{V}\right)\left(V-nb\right)=nRT$$ is applied. The constants $a$ and $b$ are van ...
4
votes
2answers
72 views

Are titration, recrystallisation, functional group analysis, etc. outdated?

In modern chemistry, - pH meter, ion electrode, AES, HPLC, etc. replacing titration - HPLC replacing recrystallisation - IR and NMR replacing melting point analysis, derivative analysis, functional ...
0
votes
1answer
27 views

Estimation of calcium EDTA [closed]

How can i estimate calcium EDTA in a given sample? We tried estimation by using mercuric nitrate but in vain we cant get a sharp end point.
-1
votes
0answers
11 views

can PMMA crosslink with vinytrimetoxysilane?

My project is on development of phase change material, which we are using myristic acid as our PCM. We have done the coating on myristic acid with PMMA to avoid acid leaking which may cause corrosion ...
0
votes
2answers
22 views

How to measure the water content of opaque liquids?

Water content of (semi) transparent liquids could be approximated via absorption spectra. What method(s) can be used to measure the water content of an opaque liquid such as milk for example?
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0answers
10 views

Theoretical Concentration (in PPM) of CO2 production after 1 minute

I recently conducted an experiment to determine ideal ratio of baking soda and citric acid that would produce the most amount of CO2 in water. We used 250ml flasks filled with 120ml water. The samples ...
1
vote
0answers
19 views

A material that could stick to almost anything? [closed]

I am looking for a material that could easily stick to any surface on impact and also detach easily. The Reason: I am making a machine for my first year Mechanical Engg. project that would throw ...
0
votes
1answer
21 views

Does conductivity change in a solution due to rust?

I plan on conducting an experiment in which I place an iron nail in water and analyze its rate of corrosion into rust with different concentrations of NaCl. My original plan was to cover the water in ...
1
vote
0answers
13 views

Can fluid catalytic cracking work on a smaller scale in a laboratory?

Fluid Catalytic Cracking usually requires a very large and tall structure. Is there a way of miniaturizing the process to fit inside a chemical lab with 10 ft ceilings? Specifically: can a fluidized ...
1
vote
0answers
6 views

How can I permanently write on HDPE plastic?

So I just spent the better part of an hour graduating a food grade HDPE 5 gallon bucket with permanent marker so I can easily fill it with water of a certain amount for homebrewing. I'm all done. The ...
1
vote
0answers
35 views

Mixing Oxalic acid and glycerin

I am doing an experiment for a miticide for honey bees I will be dissolving 600g of 99.6% Oxalic Acid in one liter vegetable Glycerin @ 150F. I have been told it will give off formic acid fumes ...
1
vote
0answers
5 views

Parameter effects on kinetics of esterification for bio-diesel production

I want to discuss the effect of parameters on the kinetics of esterification for bio-diesel production. In esterification process, temperature effect and molar ration are two important parameters. ...
4
votes
4answers
75 views

To heat or not to heat; distillation?

One of the questions in a recent past paper I completed was: One way to make water from the reservoir suitable for drinking is by distillation. Describe how water is distilled. And I ...
1
vote
0answers
23 views

Is UV-Vis absorption polarization dependent ? Why?

Consider molecule of interest be dissolved in a solvent (and this molecule has absorption in the visible region). We are using a broadband visible light source say tungsten lamp. This light passed ...
3
votes
2answers
130 views

What is the correct way to verify a structure's geometry, for example for benzene?

My goal is to compare a calculated bond length with experimental data. Benzene is obviously common enough to expect sufficient experimental data to be available for it on the internet. I have found ...
1
vote
0answers
36 views

Why are Alkali Metal Ions Soluble?

I think the question needs no elaboration. Why are salts containing Group 1A cations extremely soluble in water? I speculate that the reason involves the low charge density of those ions in a given ...
0
votes
0answers
13 views

Preparing Zwitterionic Buffer

I am trying to prepare multiple zwitterionic buffer solutions at pH 7.4. Examples include many of the following "Selected Biological Buffers" in the first table in the following link: http://www....
2
votes
1answer
14 views

Cleavage of benzyl group from alkane?

Is there a method to selectively cleave the C-C bond between a benzyl group (-CH2Ph) and a linear or cyclic alkane? Can this be done under standard conditions with somewhat widely available reagents? ...
3
votes
0answers
22 views

For alkali and lanthanide metals, is there a better liquid barrier to oxidation than mineral oil?

Most often mineral oil is used to store, protect reactive metals from oxidation. By far the best choice is to hermetically seal the metal in pure argon or some other inert gas, since, although mineral ...
0
votes
0answers
30 views

Powdering aluminum chemically?

I need a fine aluminum powder for many reactions/experiments. Could I dissolve the metal in an acid and then drop it out of solution using a base, or vice-versa? What would be the best chemicals/...
2
votes
0answers
34 views

Measuring the Kc of equilibrium between NO2 and N2O4 [closed]

I'm trying to measure the $K_c$ of the equilibrium reaction $$\ce{2 NO2 (g) <=> N2O4 (g)}$$ in different temperatures. How would I do this do this in a normal school laboratory? I was thinking ...
0
votes
0answers
24 views

Scavenging Xenon

This may well be off topic - if so I will remove it or the mods can. We will be using a good few litres of Xenon by running it through a new analytical instrument. Given it's price (at a guess, ...
2
votes
2answers
50 views

How does a copper piece added in nitric acid change after nitrogen dioxide starts appearing?

There's an experiment I have no way of performing but want to know its results. The instructions (in short) are: Dip a piece of copper in a glass of concentrated nitric acid, $\ce{HNO3}$, using a ...
1
vote
0answers
43 views

I lost salt mass after evaporation

I was doing an evaporation experiment and I used salt and water. I started off with 5 g of salt and after the evaporation process, I was only left with 4.3 g of salt. Why is this?
4
votes
2answers
146 views

Preparing an inert atmosphere reaction vessel with only an input?

One time, the graduate student that I work with was showing me how to prepare an inert atmosphere in a double necked round bottom flask. After drying it in the oven, she used a torch to drive out all ...
1
vote
0answers
23 views

Making a glow in the dark substance glow only when heat is applied

I want to make a glow in the dark substance that glows only if it gets warm. How do I obtain this substance, or what chemicals to I need to mix to make it? It's going to go in a sealed glass jar ...
2
votes
1answer
66 views

Why lithium gives flame coloration?

Theoretically speaking, beryllium and magnesium does not give flame test because:- their atoms are comparatively smaller and the valance electrons are strongly attached to the nucleus. ...
1
vote
1answer
98 views

What will be the reaction between tin (II) chloride and copper (II) chloride?

I just tried conducting an experiment during lunch today. Now, I calculated this reaction 4 days ago dealing with electrochemistry, $$\ce{SnCl2 + CuCl2 -> Cu(s) + SnCl4}$$ Theoretically, I got ...
1
vote
1answer
44 views

How to dissolve iron powder?

I know iron can react with many solutions, but when I tried to mix iron powder together with permanganate or dilute sulphuric acid, the iron powder would not react and instead, it just float on the ...
1
vote
3answers
85 views

How to interpret TLC data regarding the purity of one’s sample

The picture provided is a sketch of my TLC data from the lab along with the $R_f$ values for $i$ (initial, un-recrystallized aspirin) $= 0.429$, $a$ (acetylsalicylic acid) $= 0.429$, and $s$ (...
1
vote
0answers
26 views

Column chromatography protocol for Alternanthera sessilis to fraction phytochemicals

I'm in need to find a column chromatography protocol to fraction phytochemical compounds particularly polyphenols in Alternanthera sessilis Red. I can't seem to find one. Plus this is slightly out of ...