All Questions
44,262
questions
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Can products of Claisen Condensation undergo the reaction again?
I have a reaction of ethyl acetoacetate with 1-bromopentane in ethanol and sodium ethoxide. I understand that the main product is formed by SN2 mechanism between ethyl acetoacetate and 1-bromopentane, ...
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0
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0
answers
5
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Why are radious of H⁺ and proton different?
As know, radius of H⁺ is 0.23 angstrom, but radius of proton is about 0.84–0.87 fm. Why so much difference between them?
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0
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8
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Which one is more acidic p-bromobenzoic acid , m-bromobenzoic acid or o-bromobenzoic acid?
Just like in case of p-chlorobenzoic acid -I dominates but in case of p-fluorobenzoic acid +R dominates here which effect will dominate
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0
answers
36
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What are the reactions?
First i putted a solution of copper sulphate to a test tub then added ammonium hydroxide witch resulted in tetraamminecopper(II) sulfate:
To the same solution was added silica gel resulting in this:
...
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0
answers
26
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Synthesizing methyl 2-(2-oxopyrrolidin-1-yl)-2-phenylacetate (Revised) [duplicate]
my name is Tom and I'm a chemistry student. For the last month or so I've been doing research on how one might synthesize a methylphenidate/phenylpiracetam "Hybrid". As of now I am ...
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-1
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1
answer
40
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Thin layer Chromotography Separation
I am confused about the basic understanding when it comes to TLC. I was under the assumption that less polar compounds move farther on the plate due to it having fewer IMFs. But I also heard that a ...
-3
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0
answers
21
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a mixture weighing 4.08 g of BaO and unknown carbonate XCO3 was heated strongly [closed]
A mixture weighing 4.08 g of BaO and unknown carbonate XCO3 was heated strongly. The residue weighed 3.64 g. This was dissolved in 60 ml of 1 M HCl. What is the molar mass of X?
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22
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XRD experiment: how to interpret data and solve crystal structure from 2theta vs intensity values
I have just performed an XRD (X ray diffraction) experiment (powder), but the XRD machine I have used is not able to describe crystal data, I have $2\theta$ and intensity in arbitrary units in a UXD ...
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votes
1
answer
31
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chemical to prevent recrystallization of zinc and iron sulphate in solution
500 gm zinc sulphate and 280 gm iron sulphate ( total weight 780gm ) were taken in flask and water is added to make final volume 1 liter. the solution is heated to dissolve the zinc and iron sulphate ...
-4
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0
answers
45
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Removing added sugars from yogurt [closed]
Most of the yogurts we buy from online or offline stores contain all kinds of added sugars, which are harmful to health.
So my question is: How to remove added sugars from yogurt using inexpensive ...
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0
answers
16
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How to convert Dalton Output FIle (.out) to Multiwfn input file (.wfn)?
I just started with dalton and facing quite a few challenges in visualizing its output. I tried using Chemcraft, though its showing me some of the results like optimization steps and optimization ...
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2
answers
66
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Titration: Finding the concentration of an acid
It took almost 30 ml of 0.1M NaOH to reach the equivalence point during the titration of 20 ml of acetic acid. I need to find the concentration of protons and the concentration of my acid. I already ...
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votes
1
answer
51
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Cesium Chloride Density Gradient Centrifugation and Isotopes
In Cesium Chloride Density Gradient Centrifugation, as used by Meselson and Stahl, Cesium ions can be seen as strongly affected by centrifugation, so much so that they can overcome their ionic bonds ...
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0
answers
25
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Bleach in fish aquarium
I have a 100 gallon fish tank and my nephew decided to sdd about a cup of bleach thinking he was helping with any algae growing. I dont have access to a water supply but managed to find about 5 gallon ...
-3
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0
answers
30
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Does this Secondary Carbocation undergo Methyl Shift to convert to Tertiary Carbocation?
suppose 2-Bromobutane undergoes Sn1 in a polar solvent (say water)
Bromine would leave with H+, leaving behind a butane chain with +ve charge on the secondary carbon. The question is, before OH- ion ...
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0
answers
32
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Energy Decomposition Analysis for SN2 involving ambident nucleophiles and an alkali metal counterion
I am wanting to perform an EDA on transition state structure of the nucleophilic attack of an ambident nucleophile (2 atoms that could be used in nucleophilic attack on the same molecule) on a benzyl ...
-1
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0
answers
19
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Why does a cyclopropyl ring not stabilise a carbanion? [closed]
I mean to say that I can draw resonating structures for this carbanion as well like a Carbocation.
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1
answer
65
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Stability of H3MnO4, H2MnO4, HMnO4
I cannot seek out the reason why while H3PO4 (phosphorus oxidation +5) is relatively stable and obtainable but H3MnO4 (the same oxidation state +5) is rarely mentioned and perhaps unobtainable. HMnO4 ...
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1
vote
2
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75
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Does ferrocenium chloride ([Fe(C5H5)2]Cl) exist as a stable compound?
I am interested in using ferrocenium chloride ($\ce{[Fe(C5H5)2]Cl}$) for a synthesis application, but I couldn't find any sources referring to its existence, even though some websites and a figure in ...
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43
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What is the best Lewis structure for xenon trioxide?
I was taught, and taught many others, that the best Lewis structure for XeO3 is the one with three double bonds (the hypervalent structure). When practicing AP Chemistry questions from previous exams ...
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0
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17
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Read Annite.cif file using pymatgen
I extracted cif information on Annite from this web https://www.mindat.org/min-241.html
and, try to read its cif information using pymatgen
But, pymatgen can not read it.
it seems cif file has ...
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0
answers
39
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Semiconductors are three-dimensional crystals. So why do the models always show two-dimensional crystals?
For semiconductors such as Si and Ge, handbooks and teachers always draw two-dimensional crystals of neatly arranged atoms with 4 valence electrons each, forming covalent bonds with 1 electron each of ...
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27
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nRdT and nRTln(v2/v1) both defines work. then how work has zero and non zero value at the same time in the same process(isothermal expansion) [closed]
dH=0
dU=0
dW=0 (nRdT=0)(isothermal expansion)
but,
dW=-nRTln(v2/v1)= q (isothermal expansion)
how?
-2
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0
answers
28
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C-C Bond length in Biphenylene
Are all bond lengths equal in biphenylene? It has 2 resonating structures, so in my opinion they should all be equal. But my textbook says otherwise. Explain.
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0
answers
17
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Can both the chlorine atoms in 2-(Dichloromethyl)-propane be in same plane as carbon [closed]
In such a molecule, can those both chlorine atoms lie in same plane as the carbon they are attached to and will this compund have a Plane of symmetry
-1
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0
answers
21
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Stabilization Energy of Pi Bonds [closed]
Why do people calculate the stabilization energy of the pi bonds with an equivalent number of isolated double bonds (ex ethylene)? How would we relate relate to the structural diagram of one resonance ...
-1
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0
answers
35
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Are the following compounds Enantiomers or Identical? [closed]
So I'm in grade 11, yesterday while studying isomerism, I came across these 2 structures. They look identical to me as they've been flipped in a plane, but am I correct or are these Enantiomers. ...
-1
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0
answers
18
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Solve for assay from LOD [closed]
How do I solve for assay from the loss on drying? Right now I'm specifically looking at sodium tartrate, but I need a general idea for other compounds.
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1
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answers
26
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NMR splitting of equivalent, but separated protons
I’ve been trying to understand why equivalent sets of protons that are coupled behave as equivalent to a single coupled pair. For example in the spectrum for Diethyl ether:
Both groups of Hb are ...
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1
answer
25
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How do you perform an ion exchange of a monovalent cation with Br- counterion to a divalent or trivalent anion?
I tried to react an organic compound I have synthesized containing a di-N substituted imidazole bromide salt with Ag3PO4 with water at room temp to try to replace the Bromide with PO4(3-). I dont ...
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19
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Will increasing the initial concentration of a reactant result in more time for the reaction to go to completion?
I understand that increasing the concentration of a reactant increases its instantaneous reaction rate, but shouldn’t the amount of time for the overall reaction to go to completion increase?
For ...
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1
answer
37
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Mathematics behind the graph between Gibbs energy and extent of reaction
When the graph between Gibbs energy and extent of reaction is plotted, such a curve is obtained:
I am unable to understand how we got to the concavity of this graph (which can also be seen as the ...
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0
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21
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What is the product: Ethyne + (conc)KMnO4? [duplicate]
In cold and alkaline medium it gives ethane-1,2-dial. But what happens in conc KMnO4? Does it give CO2? Also, what will happen to other triple bond containing hydrocarbons?
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48
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How can I isolate products that cannot be cleanly distilled or visualised by TLC for column chromatography?
I am a first year PhD student in the UK, and without giving too many details of my work as it is industrially funded and my sponsors are a bit touchy over IP, I am struggling to isolate the products ...
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0
answers
39
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Why the electrons in the electrolytic cell don't flow from cathode to anode?
In electrolytic cell electrons are transferred from anode to cathode via wire. These electrons are those which are given by anion to the anode. But if anode is connected to the positive terminal of ...
-1
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1
answer
35
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Electrolysing two salts with the same anion
Assume that I prepare solutions of sodium chloride (NaCl) and potassium chloride (KCl) in equal molarity, then combine them together to form a single homogeneous mixture. Then I electrolyse this ...
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0
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27
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Comparison of intensity of color in compounds
I had given an examination recently in which the question asked was:
Compare the intensity of color in HgI2 and AgI. My approach was by checking the polarising power of the cations. But I am not sure. ...
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0
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32
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I want to know if this will be considered to be correct or not [closed]
In my exam instead of writing "the atom becomes more stable when the energy sublevel orbitals become half-filled or completely filled with electron" i wrote "the energy sublevel ...
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0
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25
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Is this mechanism of reduction using LiAlH4 followed by hydrolysis of an amide correct?
Hello everyone. I had been given a question on reducing an amide group into an amine group using any reagent I saw fit as homework. I had used LiAlH4, which provides H- and does an acid base reaction ...
-1
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0
answers
39
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I threw table salt into the boiling water and the salt fizzed, is it common? [closed]
I've been having a constant feeling of indigestion for about 3 days now and I suspect it's the tap water.
When I used table salt in boiling tap water to cook pasta, it fizzed more than baking soda in ...
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0
answers
15
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Calculation of Isomers [closed]
What is the total number of possible stereoisomers of dimethyl cyclopentane?
I tried to draw and I drew the three structures, the first one didn't contain any chiral center but the rest two contained ...
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0
answers
18
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How would you explain the graphs of exothermic and endothermic reactions?
I understand that exothermic reactions release energy in the form of light and heat. I also know that endothermic reactions absorb energy, to put it simply. However, I don't really understand the ...
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1
answer
44
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Why does graphite have a higher standard molar entropy than diamond?
It is known that graphite (5.7 J/K mol) has a higher standard molar entropy than diamond (2.4 J/K mol) (data from Physical Chemistry by Atkins). I understand that this must be due to the structural ...
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1
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0
answers
27
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How to calculate the pH of a mixture of an acid with a buffered solution?
Being a physicist by training, having worked in software development for the last 10 years. Having heard my last chemistry lecture 15 years a go I am a bit lost in regards to how one can calculate the ...
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1
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656
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Does distance exist in thermodynamic coordinates?
Consider a $P$-$V$ space. The question is a simple one: can we measure distance between two states $(P_1,V_1)$ and $(P_2,V_2)$?
Using simple Euclidian distance $d^2 = (P_2-P_1)^2 + (V_2-V_1^2)$ does ...
- 2,162
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1
answer
61
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Why is benzene more soluble than chlorobenzene in water?
Wikipedia lists chlorobenzene's solubility in water at 0.5 g/L at 20C, and benzene's at 1.79 g/L in 15C and 1.84g/L at 30C.
Chlorobenzene is very slightly polar, shouldn't it be more soluble? What ...
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0
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23
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Do we need a standard sample for the interpretation of infrared spectroscopy (IR) results? [closed]
I'm having a problem with the interpretation of the Ginkgo biloba IR spectrum, all of the articles I read never mention if there's a standard spectrum to compare the results with.
Do we need a ...
3
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0
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38
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The colour of sunset yellow powder (red, orange, and yellow)
I asked about the colour of sunset yellow in water in the previous post (Changes of colour of sunset yellow in water).
And here, I would like to raise another question based on sunset yellow.
Sunset ...
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0
answers
17
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Can 1,3-dibromocyclobutane create E and Z isomers? [closed]
Can , at least in theory, 1,3-dibromocyclobutane create E and Z isomers?? I'm asking specifically about the orientation of bromine atoms in relation to each other and hydrogen atoms on the same carbon ...
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1
answer
46
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R/S designation [closed]
Why is my answer wrong ? (Tutors answer in blue bubble)
OH is highest priority, the carbon groups are second highest priority, H is lowest priority
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