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.

Filter by
Sorted by
Tagged with
1
vote
0answers
15 views

How can I filtrate Pd2(dba)3 and P(o-tol)3? (Celite filtration failed)

I am conducting an organic synthesis involving Stille coupling, using Pd2(dba)3 and P(o-tol)3 as catalysts. Reaction solvent is toluene in which the catalysts also dissolve. Many texts said that ...
-3
votes
0answers
34 views

Data Analysis Activity [closed]

Activity Background: Five patients (Aliza Aldred, Bob Barton, Conor Chavez, Dwayne Drake, and Emma Eriksen) were administered a drug called warfarin, which is known to slow the formation of blood ...
2
votes
0answers
37 views

what does Area(A) in Randles-sevcik equation refer to? geometrical area of electrode or electrochemical active surface area/

In the Randles-Sevcik equation, $$i_p = 0.4463 \ nFAC \left(\frac{nFvD}{RT}\right)^{\frac{1}{2}}$$ we have an area $A$ in the formula. is this the electrochemically active area or geometrical area? ...
5
votes
0answers
41 views

Why is surface tension of water decreasing as sodium chloride concentration increases? [duplicate]

For my IB chemistry IA, I am measuring the impact of salinity concentration on the surface tension of water (i am using distilled water). My hypothesis is: As the concentration of salt increases, ...
-2
votes
0answers
18 views

Question about TLC [closed]

I conducted TLC to confirm Rf value of toluene. Eluent was hexane+ethyl acetate(10:1 vol). Then I used UV lamp (254 nm) to identify the spot. But there was no any spot. I had understood that toluene ...
0
votes
0answers
11 views

Common ion effect on Solubility [closed]

The common-ion effect refers to the decrease in solubility of an ionic precipitate by the addition to the solution of a soluble compound with an ion in common with the precipitate.[1] This behaviour ...
-4
votes
0answers
10 views

Van Der Waals Interactions [closed]

The radius of one sphere is 5 nm, and another sphere is 10 nm. Determine the van der Waals interaction for the following conditions: a) Distance between the spheres is 20 nm and the hamaker constant ...
-3
votes
0answers
43 views

Theoretically, given an ample supply of energy, can I convert Carbon Dioxide and Water into C6H12O6 and Oxygen in a Chamber? [closed]

Long story short, I have an insane volume of Carbon Dioxide and I have a bunch of experiments in mind. One of my questions is, would it be theoretically possible to release a high volume of Carbon ...
1
vote
1answer
49 views

Why d and s orbitals overlap even when there is considerable difference in their energies?

In my grade 11 chemistry NCERT textbook, its written that hybridization happens when orbitals of almost same energy overlaps. But S orbital and D orbital have significant difference in their energies. ...
4
votes
1answer
65 views

Does pH gets affected by pressure?

My attempt- I thought that pH is h+ ion concentration and change in volume will change its equilibrium according to le chatelier's principle . But I want to know is it correct or it needs some ...
0
votes
1answer
55 views

How to make plasma in microwave (without grapes please)?

So, I have my School Science Fair next month. We are working in teams of five with one 7th, 8th, 9th 10th, 11th and 12th grader. We were planning to make plasma in microwave but the grape method just ...
-1
votes
0answers
39 views

What will happen when an excess of hydrogen chloride gas is dissolved in water? [closed]

My theory is that the $\ce{H2O}$ molecule will act as a limiting reagent and when no more $\ce{H3O+}$ can be formed the $\ce{H+}$ which is unstable will combine with $\ce{Cl-}$ and be re-evolved as $\...
5
votes
4answers
212 views

What's the purpose of significant figures in measurements?

I have read about this topic in both of my chemistry and physics books, but none of them exactly pointed out the significance of the significant figures. Then I searched the Internet for the same and ...
-5
votes
2answers
86 views

What would happen if the alpha particles directly hit the electrons in the gold foil in Rutherford's experiment? [closed]

What would happen if the alpha particles directly hit the electrons in the gold foil in Rutherford's experiment? Would it get ionized or is there no probability of such a thing happening ?
2
votes
1answer
51 views

Is it possible to filter Stille catalysts using syringe filter?

I'm conducting an organic synthesis involving Stille coupling. Stille coupling uses $\ce{Pd2(dba)3}$ and $\ce{P(o-tol)3}$ as catalysts. Both catalysts dissolves in toluene which is the solvent of my ...
2
votes
1answer
51 views

Can the paper in thin layer chromatography be any type of paper?

I'm doing a chemistry chromatography lab that wants me to recreate anything I want. I decided to measure how far a pigment goes in each color for the same brand, but I'm stuck at the paper part. I ...
-1
votes
0answers
39 views

Why ordinary river sand does not cause alkali-silica reaction in cement etc? [closed]

Glass contains amorphous silica and the alkali silica reaction happens in cement. But why does the same thing not happen with the ordinary river sand? isn't that the same silica? as I know river sand ...
1
vote
0answers
25 views

Thickness of proton exchange membrane (Nafion)?

I am looking into using a proton exchange membrane for a bio-energy cell experiment. Previous scholars have been using Nafion as a PEM to place between the anode and cathode (air-cathode). the ...
-1
votes
1answer
61 views

How to heat up a barrel drum?

I am experimentalist, and I am unsure on how to proceed about a question I have for an experiment. In the experiment, I would like to heat up a drum barrel like: It is made of HDPE, and I would like ...
0
votes
0answers
16 views

Can ethanol and heat during distillation cause degradation/dissolution of vinyl tubing leading hot vapors of the distillate to the condenser?

I'm a chemist and a qa lab, and we occasionally test herbal remedy products from one of our customers for alcohol content using a distillation, then using the specific gravity of the distillate to ...
0
votes
1answer
80 views

At which temperature does a concentrated aqueous solution of sodium chloride begin to boil? [closed]

We know, solutes dissolved in water increases the boiling point of water. This question is an MCQ. The options are 96,99,100,104 degree Celsius. The correct answer is 96. Why? If the boiling point ...
0
votes
0answers
29 views

Why is Retention factor for Iodide greater than Bromide?

I did a separation of Bromide and Iodide ions using paper chromatography technique for 0.3% solutions of Bromide and Iodide of sodium. I got the Retention factor equal to ~0.71 for Iodide and ~0.47 ...
3
votes
0answers
34 views

Why neglecting Bradford Solution Volume in the assay?

I would like to know why do we not need to take account of Bradford agent solution in dilution calculation? For example, $\pu{2.5 \mu g mL-1}$ BSA will calculate from $\pu{0.4 \mu L}$ of $\pu{1 mg mL-...
3
votes
0answers
41 views

Can color-changing leuco dyes be used to indicate when a certain molecule binds to another in a textile fabric?

Thermochromic leuco dyes change color when the temperature changes. I want to use leuco dyes to make a color-changing fabric. However, instead of using temperature to induce color changes, I want the ...
1
vote
1answer
31 views

Three Phases in TFM test instead of two

I am currently trying to perform the Total Fatty Matter (TFM) test on soap and for some reason I am getting three phases instead of two. The surfactant used is SLES and other reagents include hot ...
1
vote
0answers
21 views

Reason for three phases in total fatty matter test on soap [duplicate]

I am currently trying to perform the Total Fatty Matter (TFM) test on soap and for some reason I am getting three phases instead of two. The surfactant used is SLES and other reagents include hot ...
2
votes
2answers
105 views

How to find the angle of emission of an X-ray during impact of accelerated cathode rays?

X rays are produced when accelerated cathode rays strike a metal target or a metal anode. How can we find the angle at which the X-ray is emitted from the metal anode or the target when the cathode ...
-4
votes
1answer
58 views

Practices while using a boiling tube

When using a boiling tube to boil a liquid, I am frequently advised to move the boiling tube in and out of the Bunsen flame and when the liquid starts to boil, remove the tube from the flame for a few ...
0
votes
1answer
38 views

Synthesis of 1-naphthaleneacetic acid: Methods

I am trying to synthesizing 1-naphthaleneacetic acid from naphthalene and monochloroacetic acid. I found some patents and papers, and I have tried to synthesis but the yield is low. I used iron powder ...
0
votes
0answers
55 views

How can I weigh the compound that melts at room temperature?

I am conducting an organic synthesis experiment involving 2,3,5-tribromothiophene. The melting point of 2,3,5-tribromothiophene is about 25-28 ℃, so it melts easily during weighing. Whenever I weigh ...
1
vote
0answers
43 views

Procedure for laboratory synthesis of tertiary amines [closed]

I am having difficulty finding a procedure for making tertiary amines in the lab, any is fine but I am specifically interested in tributylamine.
3
votes
0answers
22 views

Extract seaweed iodine from petroleum ether and cyclohexane

I'm working on iodine extraction from seaweed by using petroleum ether and cyclohexane. I have already observe the presence of iodine in the solution but I don't know how to extract the iodine in a ...
0
votes
1answer
52 views

Detection of sulphide in solution also containing sulphate

Question: The reagent(s) that can selectively precipitate $\ce{S^2-}$ from a mixture of $\ce{S^2-}$ and $\ce{SO4^2-}$ in aqueous solution is(are): (A) $\ce{CuCl2}$ (B) $\ce{BaCl2}$ (C) $\ce{Pb(...
4
votes
1answer
118 views

Can we use silver nitrate to distinguish between chloride and carbonate salts?

Initially, we are given a solution containing two salts, they can be either carbonate or chloride salts (we do not know their composition initially). Generally, $\ce{AgNO3}$ is used as a confirmatory ...
3
votes
0answers
15 views

Safety concerns (Cyanide): Dicyandiamide + Polyamine condensation reaction

I am attempting to synthesize a poly-amine polymer by condensation between dicyandiamide (also known as cyanoguanidine and dicyandiamine) and diethyltriamine. The polymer is a kind of dye fixative ...
5
votes
1answer
35 views

Carbon 11 radiolabeled inhaled Beta-2 agonist or corticosteroids, is it possible?

Background Positron emission tomography (PET) is a highly sensitive imaging modality that can provide in vivo quantitative information of biological processes at a biochemical level. PET relies upon ...
0
votes
0answers
30 views

Measuring Cylinders — small or big?

My teacher often recommends the usage of a smaller/more narrow measuring cylinder over a larger one while performing experiments but why is that? Does it help in accuracy in any way?
0
votes
0answers
36 views

What is the literature value of the activation energy of the reaction between iodate and bisulfite?

I explored the Arrhenius equation using the reaction between potassium iodate (containing the IO3- iodate ion) and sodium metabisulfite (bisulfite ion), however I can't find a literature value to draw ...
-1
votes
2answers
60 views

Enthalpy vs. delta enthalpy

I haven’t really found a clear answer. Enthalpy is measured as the sum of internal energy (kinetic and potential energy) and pressure times volume. However, I don’t really see the value of measuring ...
0
votes
1answer
48 views

How to make silicic acid, potassium silicate or calcium silicate?

I am a student of tropical agriculture. I am taking the class of agronomic chemistry and plant nutrition. I want to make use of silicate source I have at home for e.g. zeolite, wood ashes, ...
2
votes
1answer
27 views

Diffusion of multiple gases at once

Graham’s law of diffusion states the rate of diffusion between two gases is inversely proportional to their molar masses. Now, this is helpful when we are focused on two gases. But that is rarely the ...
1
vote
3answers
131 views

Safe chemical reactions to start a campfire [closed]

I'm looking for a way to start a small fire electronically with widely available chemicals. It would be great if they are safe to use with metals (not necessarily). But the biggest requirement is that ...
2
votes
0answers
22 views

Is there a known value for the molar extinction (absorption) coefficient for amylose and amylopectin iodine complexes?

I am doing a colorimetry experiment with starch, and have a theoretical model based on Beer's law. To solve it, I need a known value for the molar extinction coefficients of amylose and amylopectin ...
0
votes
0answers
14 views

How reliable would commercially available starch be as a standard for an experiment?

I am conducting a student experiment of finding the amylose to amylopectin ratio of certain samples using an iodine colorimetry method. In order to calculate the actual ratios, I need a standard to ...
1
vote
0answers
20 views

Are there any tests which distinguish between triglycerides and polar lipids/impurities that can be conducted in a high school setting?

I am currently writing a research essay about using a mixed polar (methanol) and non-polar (heptane) solvent system to extract oil from mango seed kernels. One of the difficulties of using polar ...
-4
votes
0answers
89 views

The things you wish you would have done before doing a PhD in Organic Chemistry? [closed]

Hello there fellow chemists. I am really interested in doing a PhD in Organic chemistry. I haven't really thought which field I would like to specialize in, but it's definitely on my mind ever since ...
1
vote
2answers
76 views

Triple Point of a compound and critical point

Is it necessary for all compounds to have a triple point? Also, how is the triple point determined? Suppose a substance does not have a triple point, so how do researchers agree on the impossibility ...
-5
votes
1answer
214 views

How do you distinguish ferrocene, acetylferrocene and diacetylferrocene in a NMR spectra? [closed]

I made an experiment where I made a Friedel-Crafts acetylation of ferrocene. Now I would like to know if/how I can distinguish ferrocene, acetylferrocene and diacetylferrocene in a NMR spectra? For my ...
2
votes
0answers
48 views

What does Molecular Orbital Theory allow you to predict?

Molecular Orbital theory reveals the outcome when two atomic orbitals overlap. Almost all of the time we draw a Y axis with the notation of energy that can be described using electron volt units (eV). ...
2
votes
1answer
50 views

How to Test Auto-Ionization of Ammonia

I was wondering how we could test that the auto-ionization of liquid ammonia actually occurs experimentally. The chemical equation is described below: $\ce{NH_3 <=> NH_4^+ + NH_2^-}$ I was ...

1
2 3 4 5
30