All Questions
42,975
questions
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3
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Field effect in Sn1?
Recently my friend asked me about reactivity of following compounds in Sn1 :
(1)2-Chloro 2,3-dimethylbutane
(2)2-chloro 2-methyl butane
(3)2-chloro 2-methyl propane
My reasoning: 3>2>1 due to ...
0
votes
0
answers
3
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Why does gallium expan on solidification
I've heard that Ga exist as Ga³ molecules in its crystal lattice. Does that have anything to do with expansion of Ga while solidifying? Why and how does it actually expand?
0
votes
0
answers
7
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Why is temperature not varying with voltage in a daniel cell?
I am conducting a lab on effect of temperature on the daniel cell, but I am getting an increase in voltage with temperature.
I'm using 50ml of 1M ZnSO and 0.1M CuSO4, connecting it in circuit and ...
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-1
votes
0
answers
18
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Conformational Problem of L-lyxose
I've been asked to draw the open-chain form of L-lyxose (C-2 and C-3 epimer of ribose), given a diagram of D-Ribose
However, this is the answer given.
I'm confused on why this answer is correct. Does ...
-2
votes
0
answers
27
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The nomenclature of heterocycles [duplicate]
I would like to know the method of naming (from chemdraw software) the molecules carrying this skeleton:
I want to know How the indexes [2',3':4,5] and also [1,2-c] are used in this nomenclature (I ...
- 1
0
votes
0
answers
38
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Can someone elaborate what it means when its said that electron shells do not exist in multi electron systems?
I'm an undergraduate student in chemistry. I'm trying to grapple with all the new stuff we're learning and making sense of it. Now I want to know if electron shells really "exist" in multi ...
- 19
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votes
0
answers
42
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Theoretical explanation for: Why is KMnO4 stronger oxidizing agent than K2Cr2O7?
I know that it can be explained using the Reduction Potential values. But, can it be explained from their structures or something like that ?
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votes
0
answers
47
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How to store powder milk for years?
I have 25kg of skimmed powdered milk in a thick paper bag. It is unopened. The packaging is like this, which is a hermetically sealed polythene lined 2-ply kraft paper sack:
My plan is to open it, ...
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-2
votes
0
answers
17
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The methodology of sodium ethoxide in condensations
When people perform claisen condensations and Darzen condensations the common methodology is to Add sodium metal to ethanol or methanol forming sodium ethoxide or methoxide respectively; this is ...
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1
vote
1
answer
84
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Is CD4 an alkane?
Can $\ce{CD4}$ or $\ce{CT4}$ be considered an alkane?
I know that an alkane is $\ce{C_nH_p}$ where $p = 2n + 2$. An alkane is considered a "hydro"carbon, i.e., a compound containing purely ...
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-1
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0
answers
9
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are black holes black body? [migrated]
I've read online that black holes are almost ideal black bodies. But for a body to be called an ideal black body it should emit all the rays of all the wavelengths but black holes don't, so how can we ...
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-5
votes
0
answers
15
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Can Oleamide Reverse to Oleic Acid? [closed]
Same as the title. Can oleamide reverse to Oleic Acid?
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-2
votes
1
answer
60
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If I know the freezing point of two solutions, and combine them into one solution, what is the resulting freezing point?
I am not knowledgeable in chemistry in any way, so I'm sorry if I seem stupid or something.
Suppose I have two solutions which I know the freezing point of, and I combine them into one solution. How ...
-2
votes
0
answers
23
views
Enthalpy change equation [closed]
I'm trying to understand the enthalpy change equation where $\ce{\Delta E + pV}$ is substituted in for ${\Delta H}$. The substitution is stated to be:
${\Delta E+pV = q(p) + w + p(\Delta V)}$
I ...
- 1
-5
votes
0
answers
25
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I was wondering what a graph would look like where you plot time against the temperature at which you heat a mixture of naphthalene in acetone [closed]
The solution is very concentrated. 4 grams of naphthalene is put in 25 mL of the concentrated acetone.
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-3
votes
1
answer
47
views
Why does atomic radius decrease across periods?
My textbook says that this happens because the number of protons, and thus the total positive charge, increases - a greater attractive force acts on each electron. The book says that this is despite ...
- 19
-1
votes
1
answer
54
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How can I protect the ester group from reduction?
If I process this reaction the NaBH4 will also reduced the ester group to alcohol. I want to convert the Nitro (-NO2) functional group to Amine (-NH2) without disturbing the Ester group. So, my ...
- 3
0
votes
2
answers
78
views
Which is more acidic, alcohol or phenol?
My teacher taught yesterday that though resonance happens in phenoxide ion, it is less stable because the negative charge gets distributed over the carbons in the ring. And hence, alcohols are more ...
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-5
votes
0
answers
44
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Stoichiometry problem [closed]
The problem is:
Let m (grams) of mixture E consisting of one peptide X and one peptide Y (know the number of nitrogen atoms in X, Y are 4 and 5, respectively, X and Y contain glycine and alanine ...
-3
votes
1
answer
55
views
Degree of Unsaturation or Index of Hydrogen Deficiency
I know the formula for the DOU, but don't really understand why the formula works. Could someone elaborate that to me?
-2
votes
0
answers
34
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Reduction by H2/Ni
I have learnt that H2/Ni reduces nitro-alkanes to amines.What is the mechanism for this reaction?
Are nitro-arenes(e.g. nitrobenzene) also reduced by H2/Ni?
And what is its effect on R-NO or Ar-NO?
[R-...
- 103
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votes
1
answer
38
views
Why does an exothermic/endothermic reaction have a negative/positive enthalpy
So regarding change in enthalpy and exothermic/endothermic reactions, I think I have some conceptual understanding but I'm missing some things.
My current understanding is that:
Given a reaction, if ...
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-3
votes
0
answers
20
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Resonance is weighted mean of individual energies of conical structures [closed]
I read this in a book
But then how can the value of weighted mean be less than all the individual energy values ?
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-2
votes
0
answers
22
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Chemical formula on non-stoichiometric compounds
I have a question regarding the compound, Cs$_{0.1}$FA$_{0.9}$PbI$_{2.865}$Br$_{0.135}$, which I noted as a non-stoichiometric compound due to the fractional subscripts. (I am not a chemist, so ...
1
vote
0
answers
36
views
Gibbs Free Energy - Maximum Work
I've been having a lot of trouble trying to truly understand Gibbs free energy from a practical perspective. I have no background in physical chemistry, but I think I have a firm grasp on many of the ...
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-3
votes
1
answer
70
views
What is the equivalence point in the context of a redox titration?
We know the standard reduction potential of the species: $\ce{Fe^{3+}}/\ce{Fe^{2+}}$, $\varepsilon_1$ and the standard reduction potential of the species: $\ce{MnO_4}^{-}/\ce{Mn^{2+}}$, $\varepsilon_2$...
-6
votes
0
answers
39
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Why is the bond length of [O2]+ more than [O2]? [closed]
According to the data obtained from https://www.wiredchemist.com/chemistry/data/oxygen-selenium-compounds:
The Bond length of [O-O] in O2 and O2+ are 1.208 and 1.227 respectively, according to MOT ...
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-1
votes
0
answers
34
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What is the exact meaning of enthalpy, and what is the difference between enthalpy and the change in enthalpy? [duplicate]
I know that H=U+PV, I understand the concept of internal energy U but what about the pressure and volume, the pressure of what? Is it pressure Applied on the system?
More importantly I know as a fact ...
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-2
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0
answers
42
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Quantum computers and the future of quantum chemistry
Our inability to make accurate predictions on the behavior of complex molecules or atoms comes from the fact that solving the time independent Schrodinger equation is hard and unless a very big ...
- 133
-1
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0
answers
53
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Creating molecules from cartesian coordinates of atoms
I am trying to generate molecules from just the coordinates of the atoms which also have some uncertainty to their location (up to 0.3Å). This is harder than I thought, I have tried using "...
- 9
0
votes
1
answer
80
views
Are there xenon compounds with two xenon atoms bonded directly to each other?
I've seen so many compounds containing xenon, and xenon was mostly the central atom, and if we had 2 xenons they would never bond directly to each other. I was curious if it is possible to have for ...
- 19
5
votes
0
answers
40
views
The 'bite size' effect in chelating ligands
My question is in relation to the following data, which describes the log K for the equilibrium of Mn+ + Ligand $\ce{<=>}$ [ML]n+
As far as my understanding goes, this is an example of the ...
-2
votes
0
answers
37
views
Why are alloys considered mixtures? [closed]
The different elements or atoms in alloys will experience metallic bonding to one another. Metallic bonding is an intramolecular force so are they not chemically bonded and therefore a compound?
Water ...
- 203
3
votes
1
answer
254
views
Empirical formula and rounding
I am very confused with the procedure to find the empirical formula. In the part where we have to multiply by subscripts to make them integers, are there clear rules?
For example, if I have the ...
- 139
-1
votes
0
answers
16
views
What causes the difference in the appearance of the peaks in the spectra for the free salen ligand and [Co(salen)] [closed]
The only difference I can see between these two spectra is that the peaks in the region under 1600cm^-1 appear to be narrower in the complex than in the free ligand and I don't understand why.
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-4
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0
answers
55
views
If 50.0mL of 0.100M C6H5COOH (Ka = 6.3 x 10-5) is neutralized by 50.0 mL of 0.100M NaOH, what will the pH of the final solution be?
I've tried a few different ways to answer this question and gotten the wrong answer every time. It is supposed to be 8.45, but I have gotten 4.2 no matter what I try. Please help.
The main thing three ...
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-4
votes
0
answers
12
views
Rounding when finding the reaction order [closed]
If I were to find the reaction order and the answer is 1.5454281, would I round to 2 or just keep it at one? thanks!
-1
votes
1
answer
74
views
Is the dissociation constant still defined at all if one goes beyond the maximum solubility?
If you go beyond the solubility product, [KA] continues to grow and [K+], [A-] remains the same. So the dissociation constant ([K+][A-])/[KA] should suddenly become smaller and is therefore no longer ...
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votes
0
answers
29
views
Why do endothermic reaction even occur? lies [closed]
What's the parameter that defines some compound's / species existence?
if stability lies in where a compound lies in terms of relative potential energies and the one with lower energy is supposed to ...
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4
votes
0
answers
57
views
What is the driving force of Bartoli indole synthesis?
The Bartoli indole synthesis mechanism begins with a series of attacks on the nitroarene regent by the Grignard reagents. But the atom $\ce{O}$ in $\ce{-NO2}$ should be negative, and Grignard reagent ...
- 49
0
votes
1
answer
49
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How to shift SO3/SO2 equilibrium?
I am struggling with a chemical equilibrium question and would appreciate some help. The question involves a closed system where the equilibrium
$$\ce{2SO2(g) + O2(g) <=> 2SO3(g)}$$
has been ...
-3
votes
0
answers
30
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Help with balancing a chemical equation and optimizing reaction rate [closed]
I am having trouble with a chemistry question and was hoping someone could help me out. The question is as follows:
Nickel reacts with hydrochloric acid to form nickel(II) ions and
hydrogen gas.
a) ...
-2
votes
0
answers
22
views
Replacement solvent for Ethyl lactate [closed]
Is there a replacement solvent for Ethyl lactate used in a formulation of an urethane adhesive for bonding urethane to metal in a molding process
-2
votes
0
answers
27
views
What is the correct name of the compound according to IUPAC nomenclature [closed]
Which is the correct name of the compound shown in the photo attached to this, according to IUPAC nomenclature. Is it 2-Bromo-5-chloropentane or 4-Bromo-1-chloropentane. And what are the rules of ...
-1
votes
0
answers
12
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Derivation of Ebullioscopic constant Formula [duplicate]
How can I derive the Ebullioscopic constant formula
??
{PS: I am yet a high school student. Please explain the symbols used in each step.}
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votes
0
answers
12
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Chemicals in a Rubber Adhesive - QC 136-1, Pegasol 2530, Santiczer 160, Agerite White, Altax and Cerechlor 70L [closed]
I have a recipe for a rubber adhesive and am trying to understand some of the ingredients. Some of my research indicated what these are but looking for replacement products?
They are:
QC 136-1 - Don't ...
-2
votes
0
answers
47
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What should be the major product of this reaction? [closed]
In this question, I am having confusion regarding the major product as all of them seem to be possible except option 3. What should be criteria to decide major product in questions like this where ...
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0
answers
18
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Ps4 controller shell cleaning [closed]
I tried cleaning a PS4 controller shell with a mix of Dawn dish soap and warm water, and I used a toothbrush to scrub. I have taken apart the electronics and used 70% isopropyl alcohol for the ...
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-5
votes
1
answer
36
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What is the abundance order of all the s block elements? [closed]
NCERT gives the answer for group 1 and 2 separately and does not provide a combined answer.. it just states that mg ranks 6th but what are top 5 elements isn’t mentioned…
-5
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0
answers
32
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Bagaimana sifat magnet dari logam transisi [closed]
Bagaimana sifat magnet dari logam transisi, oksida logam, logam tanah jarang dan senyawa kompleks?
