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26 views

What will be the Lewis acid and Lewis base in the reactions between aluminium(III) aqua complex and hydroxide?

$\ce{Al^3+}$ in water will be hydrated, formed a complex ion $\ce{[Al(H2O)6]^3+(aq)}$ that can neutralize hydroxide ion according to the following reactions: $$ \begin{align} \ce{[Al(H2O)6]^3+ + ...
3
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1answer
59 views

Point group of cis- and trans-decalin

What is the point group of of cis- and trans-decalin? I watched a video saying that it is $C_\mathrm{2h}$ for cis-isomer, but my friend says it is $D_\mathrm{2h}.$ I'm so confused.
2
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1answer
30 views

In Flame Emission Spectroscopy, what part of the flame is used to measure the concentration of the analyte?

Flame Emission Spectroscopy is an analytical measuring device that relates the intensity of the emitted light relative to to the concentration of the sample. As I am reading an article about FES, I ...
0
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0answers
28 views

How to reduce hydroxylamines to amines?

What would be suitable compunds to reduce an hydroxylamine to the corresponding amine? I couldn't find scientific papers on that except Indium-Mediated Reduction of Hydroxylamines to Amines , but it ...
3
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0answers
19 views

IRC analogue of conical intersections and minimum energy crossing points?

In my project, there are some spin forbidden organometallic reactions that involves both the triplet minima and singlet transition state (TS). Using the penalty method in qchem as well the method of ...
-2
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2answers
55 views

Out of CaCO3 and MgCO3, which has higher electrical conductivity of molten solution? [closed]

According to me, Mg will be more hydrated and so should have lesser conductivity. Is that correct?
6
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3answers
442 views

In High Performance Liquid Chromatography, why are ratios of solvents used?

How do they allow for better separation? For example, why isn't 100% hexane used?
0
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0answers
16 views

Nickel electroplating diamond grinding wheels

We can electroplate nickel on steel base with any density as we wish. For small diamond grits by pumping the solution we can electroplate the diamonds on the tool. But after some testings we find ...
0
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2answers
63 views

Doubt in the word infinite dilution [closed]

At times I find the concentrations being expressed as weight percentage. However I do not understand why molarity is not chosen. Secondly, which close reference to the problem that I have been facing ...
1
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1answer
43 views

Euclidean distance between atoms using RDKit

I'm trying to find the Euclidean distance between two atoms in the molecule with SMILES representation O=CC1OC12CC1OC12 using the ...
0
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0answers
15 views

How to determine if ChEMBL compound is an `agonist` or `antagonist` in assay?

In the ChEMBL database, there is an assays table that contains a standard_type column. In our case, we care only about ...
2
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1answer
40 views

Why there are more examples of carbonylate anions than metal carbonyl cations?

I know that metal carbonyl complexes that do not follow EAN rule or 18 electron rule try to achieve that by gaining electron (forming carbonylate) or loosing electron (forming carbonyl cations). But ...
1
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3answers
135 views

What are the effects of radio waves on matter?

Different regions of the electromagnetic spectrum interact differently with matter: Microwave radiation can induce molecular rotation. Infrared radiation can induce molecular vibration. Visible and ...
5
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3answers
106 views

The concept of normal coordinates of a molecule

Sometime ago I had posted the What is the origin of "normal" in normal coordinates and normal modes? in math & sci history problems. Nobody was sure for the reason for using the word normal there -...
1
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0answers
37 views

What is the degree of freedom of the calcium carbonate dissociation reaction?

Question $\ce{CaCO3}$ dissociated in a closed system according to the reaction: $$\ce{CaCO3(s) -> CaO(s) + CO2(g)}$$ Assuming the reaction is in thermodynamic equilibrium, what is/are ...
1
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0answers
15 views

Organic solvent for cleaning autosampler syringe

I work in a laboratory where gas chromatography is used extensively. We handle phthalates. What are the possible wash solvent for autosampler syringe? I've been using acetone.
1
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0answers
34 views

Identifying endothermic and exothermic reaction [closed]

How can I know that a given reaction is endothermic or exothermic? I know that all combustion reactions are exothermic. But what about other reactions? In my school exam I was asked about whether the ...
0
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0answers
18 views

What is the cause of yellow discharge in beaker during the electrolysis of copper electrodes using copper sulfate electrolyte?

I have conducted an electrolysis experiment using a copper anode and cathode, and copper sulfate solution in a beaker connected to a power source using alligator clips. I varied the voltage and ...
1
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1answer
34 views

Why is Q/nF equivalent to the amount of substance in electrolysis?

I am told that $$Q = nF$$ where $Q$ is the quantity of current, $n$ is the amount of electrons and $F$ is Faraday's constant. Since Faraday's constant is the charge carried by 1 mol of electrons, ...
-1
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1answer
46 views

The reaction of Group 14 to get its full shell

I was learning about group 14 of the periodic table and in the course, on Alison (link at the bottom), it said a reaction of the elements in group 14, they use group 4, would consist of sharing ...
0
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0answers
24 views

Electrolytes for Anodization at Home

I'm looking into anodization, and all the people doing it seem to have sulfuric acid as their first choice electrolyte, while others use sodium metabisulfate. Having simple access to exactly neither ...
2
votes
1answer
21 views

Character table and symmetry operations

It's been a while since I've dealt with these, but do character tables include all possible symmetry operations? I am looking at the $D_{\infty h}$ point group table and it lists $C_\infty$, $\...
1
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1answer
293 views

DNA pairs (adenine-thymine, guanine-cytosine) [closed]

Well I was wondering why adenine pairs with thymine and cytosine pairs with guanine. From those pictures: Thymine has the lowest acidity and adenine has the biggest acidity. So it is logical that ...
0
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1answer
96 views

How do I calculate the ensemble-average net charge of an amino acid at given pH?

I am given an amino acid with an ionizable side chain at a certain pH. How do I determine the net charge of that amino acid when there are mixed protonation states of one or more of the groups at that ...
-1
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2answers
50 views

Chemistry Vs. AutoMobile Industry [closed]

Well, it may not sound deeply related to chemistry but my question is to some chemistry-experts who knows bit about automobile industry. I want to ask, if a person is getting graduated by having ...
0
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1answer
62 views

Why has nature evolved to put a porphyrin (i.e. chlorophyll) as the chromophore in a leaf? [closed]

I'm stumped by this question: Why has nature evolved to put a porphyrin (i.e. chlorophyll) as the chromophore in a leaf? I've thought that it might have something to do with how sun emits light ...
-1
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0answers
19 views

Why do the resonance structures of carbon-monoxide not show complete octet and not contain the same number of unpaired electrons?

I came across the resonance structures of carbon-monoxide while studying as given on Wikimedia: Two of the rules for writing resonance structures given in my textbook states that: "the ...
5
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0answers
46 views

How to extract force constants for normal modes from ORCA?

I am following the computational method described in Scientific Reports.[1] Where the authors analyze the contribution of each excited state normal-modes to the shift of the transition energy. For ...
0
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0answers
112 views

Why is Thorium (At. no. 90) an f-block element at all?

Being an exception of the Aufbau principle, Thorium has an electronic configuration of $\ce{[Rn]}\mathrm{7s^25f^06d^2}$ instead of the expected $\ce{[Rn]}\mathrm{7s^2 5f^2 6d^0}$. Two other elements, ...
0
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1answer
21 views

what will be the priority order?

if any two compounds happen to show tautomerism, ring chain isomerism, functional isomerism, metamerism, chain isomerism as well as position isomerism, what priority order do we follow to assign them ...
1
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1answer
67 views

Software that determines whether a molecule can exist and draw it from a formula?

I have run calculations that predict atomic configurations. As a simple example, in a system that contains H and O, I might get a list like: ...
-1
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0answers
12 views

Conformational analysis

I have a question which asks me to find the most stable Newman projection of 2 methyl pentane....do they need to specify about which carbon? Please just tell me yes or no I will solve it by myself. ...
0
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3answers
1k views

Are all volatile liquids combustible?

I realized that liquids like petrol, kerosene and even perfumes are combustible when they are volatile. Could that be the reason why water is not combustible is because it is not volatile? Are ...
5
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2answers
52 views

Freely available software for generating 3D coordinates of molecules

As part of some research I am doing, I want to do a head-to-head comparison of software for generating 3D atomic coordinates for molecules. Is there a list anywhere of chemical software that does this?...
0
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1answer
47 views

Is sugar in mead different from “regular sugar”?

My understanding of the process of making mead is that you combine honey, yeast and water in an anaerobic environment. The yeast-bacteria ferments the sugar in the honey and produces ethanol (among ...
3
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0answers
42 views

Why does Potassium Sorbate have two CAS numbers? - Should these not be unique?

Potassium Sorbate has two CAS numbers - 24634-61-5; 590-00-1. Should these not be unique?
0
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1answer
33 views

Iodine formation reaction

$$\ce{IO3-(aq) + 5I-(aq) + 6H+(aq) -> 3I2(aq) + 3H2O(l)}$$ Why does the reaction between iodide and iodate ions have to occur in an acidic medium ($\ce{H+}$) to form the iodine? what do the $\ce{H+}...
0
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1answer
49 views

Fischer's proof of the structure of glucose

To differentiate between Mannose and Glucose , Fischer developed a series of reactions to make the aldehyde group to alcohol and terminal alcohol to aldehyde. What was this series of reactions ? Even ...
-1
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2answers
21 views

resonance structures and formal charges

hey so I have been stuck on this question for the past few hours and I can't seem to figure it out. I am moving the pi bond one carbon/bond at a time but I can't seem to come up with the correct ...
-1
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0answers
26 views

Significant Figures - Mixed Operation

I've been using an onling significant calculators in order to verify most of my calculations in order to see if I had the correct amount of significant numbers, but there is one exercise where I can't ...
1
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0answers
42 views

Calculating thermodynamic quantities for hydrogenation of iron nitride

HW#6.3 If the reaction $$\ce{Fe2N(s) + 3/2 H2(g) <=> 2 Fe(s) + NH3(g)}$$ comes to an equilibrium at a total pressure of $\pu{1 bar},$ analysis of the gas shows that at $\pu{700 K}$ ...
3
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1answer
53 views

Are there chemicals that absorb and release upon heating oxygen more efficiently than potassium oxide?

$\ce{K2O}$ absorbs oxygen forming $\ce{K2O2},$ which decomposes to $\ce{K2O}$ and $\ce{O2}$ at 500 °C. This means that $\ce{K2O}$ can absorb up to 17% its mass of oxygen. Are there other substances ...
-1
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0answers
37 views

What is the significant figures in error percent?

As an example, the value I got was $\pu{0.254 g}$ and the accepted value is $\pu{0.294 g}$. I'm trying to calculate the percent error. $0.254 - 0.294 = -0.04$ (error) $-0.04/0.294 = -0.1360544... \...
2
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0answers
76 views

Why can't calorimetry be used to measure fast reactions?

As my previous post was a bit unclear and unspecific, I am reformulating it. First of all this is a question that I had while reading some concepts my book introduces, so this isn't a homework ...
1
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0answers
33 views

Increase of peak intensity in case of hydrogen bonding

Typical motif in case of hydrogen bonds is charge transfer from electron rich acceptor Y to (usually) anti-bonding X-H σ* orbital. If so, the X-H bonding distance increases, bond weakens, stretching ...
1
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1answer
63 views

Haworth's research of glucose

Firstly haworth used CH3I/Ag2O with glucose which replaced 5 H by CH3 forming a acetal which locked the anomer and stopped the equilibirium of ring chain tautomerism. Under dilute acidic conditions ...
0
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1answer
44 views

How ethylbenzene and 1,2‐xylene are chain isomers?

How the following two structures are chain isomers? According to what I have studied in nomenclature when a compound has both cyclic and straight chain, we consider that the chain as parent chain ...
1
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0answers
35 views

Which DFT functional is best for predicting macroscopic properties of molecular liquids?

Which DFT functional (KS-DFT, to be more specific) performs best at predicting macroscopic properties (density, surface tension, boiling point, relative permittivity etc.) of molecular liquids (...
0
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0answers
16 views

Contraction in Lanthanides and Actinides

How does the lesser shielding effect of 5f electrons(relative to 4f electrons) reduce the change in atomic radius (here, metallic radius) between 2 consecutive elements in Actinides (when compared ...
0
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1answer
39 views

Why does boiled water have a different taste as compared to cool water? [closed]

I have noticed it frequently and decided to check with some of my peers and friends about this and they too have felt such a thing. The taste comparison occurs after the boiled water is cooled down to ...

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