Newest Questions
46,142 questions
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what factors would affect the change in the concentration of the hydrogen in the plateau region for the metal hydrides?
I was trying to understand that in the plateau region of the PCT curve , we use the Van't hoff Equation, even if we considered the sloping factor we will have the following equation:
$\ln(\frac{P}{P_o}...
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Calculating Amperage needed for Electroplating Copper
Im trying to determine what amperage is needed to plate 1oz copper with nickel.
So what i found from research is that you can use this formula: I=$\frac{Q}{t}$
and using Faraday's first law: $Q=\frac{...
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Redissolving calcium carbonate after heating
I need to redissolve calcium carbonate in a water sample after evaporating some of the sample, which I expect will cause the calcium to precipitate. I'm thinking a relatively weak acid is best to ...
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24
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Tracking dependent reactions and reactants using stoichiometric matrix for a very complex system of equations
I am modeling a metabolic network of signaling pathways through a system of ordinary differential equations
$$
\frac{dX}{dt} = F(X) = S v
$$
where $X$ is the vector of molecules (121 in my case) ...
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What can go wrong in synthesising MOFs that would lead to oxide formation and not a MOF?
I'm trying to synthesis a MOF through a solvothermal method, using metal nitrates and 2-methylimidazolate (2-MeIM) as precursors, $\ce{MeOH}:\ce{H2O}~(35:5)$ as solvents, and cetyltrimethylammonium ...
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Where does Conjugate base [A-] concentration come from in HA dissocation that is used in derivation of kb*ka=kw?
Suppose in reaction: $\ce{HA +H2O <=> H3O+ + A-}$
$K_\text{a}=\dfrac{[\ce{H3O+}][\ce{A-}]}{[\ce{HA}]}$
And then conjugate base $\ce{A-}$ reacts with $\ce{H2O}$
$$\ce{A- + H2O <=> HA + OH-}$...
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What is the effect of an applied magnetic field on crystal field splitting?
I was just learning about complex ions in my chemistry course. We further learnt about the factors that lead to the crystal field energy splitting of the d orbitals. One of which is orbital overlap (...
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45
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Is entropy constant when no heat is transferred?
Does entropy remain constant in when no heat is transferred between the system and surroundings?
If I do only mechanical or electrical work to change the properties like the volume of the system, ...
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35
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Jahn-Teller effect in a square planar configuration
In the original paper of Jahn et Teller (https://royalsocietypublishing.org/doi/pdf/10.1098/rspa.1937.0142, section I-Two Examples) are described two examples: a linear molecule and one with square ...
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How does adding a different solvent affect the position of equilibrium?
Let's say we have an equilibrium in an aqueous solvent, for example:
$$\ce{[Co(H2O)6]^{2+}(aq) + 4Cl^-(aq) \leftrightharpoons [CoCl4]^{2-}(aq) + 6H2O(l)}$$
What happens if I add a miscible solvent ...
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1
answer
127
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Which tautomer of nitrous acid is more stable?
I found that there are $2$ possible structures for $\text{HNO}_2$, both of which are tautomers comprising a diad system:
Why is the former more stable? It should be so as I have seen this structure ...
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41
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Anhydrides of -ous oxoacids
Why don't the oxoacids of Nitrogen and Sulphur having a oxidation state less than the maximum (i.e. less than 5 and 6 respectively) form anhydrides?
For example N2O3, which should be nitrous anhydride ...
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Why exchange interaction only occur between particles with parallel spin?
I was reading and (still) trying to understand Hartree-Fock Theory.
I read that exchange interaction only occurred between particles with parallel spin, and not the opposite spin, which is why there ...
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1
answer
16
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How does a change in potential energy of molecules lead to a change in kinetic energy?
When I think about other types of potential energy, it seems like there is a mechanical equilibrium, or a balance of forces. Then, when one force changes, movement occurs. For instance:
A brick ...
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35
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Why can't the aldehydes tautomerize in the reaction of Aldehydes with PCl5 to form alkyl chlorides?
My teacher gave us this question where CH3CH=O (ethan-1-al) reacts with PCl5 to form geminal dichloride CH3CHCl2 (1,1-Dichloroethane).
CH3-CH=O + PCl5 → CH3-CHCl2 + POCl3 + HCl
He explained the ...
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28
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what is the cloride in water? [closed]
You work in the waterworks in Drammen municipality. To ensure safe and good drinking water quality for the municipalities' residents, sodium hypochlorite (chlorine) is added to the water to disinfect ...
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38
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why does a carbon-halogen bond make that carbon less acidic (in this case)?
A question I came across treats this molecule with KOtBu which forms an anion...
The correct anion is:
An incorrect anion is:
I don't understand why this is - I'd have thought that the C of the C-...
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1
answer
40
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Geometry Optimizations for Excited States
I am studying computational photochemistry and I am confused about some steps. I would appreciate any help someone could offer.
I was asked to perform geometry optimization for excited states. However,...
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27
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What is the difference between a 3c-4e bond vs 2 covalent bonds?
A 3c-4e bond is a bond in which 4 electrons are shared between 3 centers, but 2 covalent bonds between 3 atoms is also the sharing of 4 electrons between 3 centers (according to MOT)? Where is the ...
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0
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17
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Reaction of Prenol with Thionyl Chloride [closed]
What would be the major product in the said reaction?
Prenol is just
So my doubt is that, I was thought that when there is allylic alcohol present in the reaction with SOCl2, it does SN2' reaction ...
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26
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Retrosynthesis of a target molecule [closed]
Using the starting material (SM) explain the retrosynthetic analysis by which the target molecule (TM) can be obtained
SM is parabromobenzenesulphonic acid
TM comprises of two benzene rings.
One ...
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29
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Temperature of thermal dissociation of carbon monoxide?
I was reading a paper about CO2 splitting, which mentions limitations of high temperature approach:
NTP even in the presence of solid catalysts is not able itself to
effectively promote the CO2 to C +...
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43
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What type of gas will stay in a latex balloon the longest – regular air, helium, and argon? Why?
I filled up balloons with the different gases and measured their circumference every 12 hours. By the end of the 96-hour period, the regular air balloons had decreased by only 1.8%; the helium ...
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1
answer
122
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TDDFT Results - Excitation Energies
I ran some vertical excitation energy calculations, and I'm a little confused about the results. Would someone be able to help me to understand?
Here are my results:
I'm trying to understand the ...
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0
answers
22
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Do protons present in a nucleus shield each other from interactions with the electrons?
Its well documented that inner electrons shield outer electrons from the influence of the nucleus, and the consequences of this have also been reported and analyzed. However, with a large enough ...
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Finding activation energy using a graph [closed]
I’m trying to find the Activation energy of this graph ( it was a reaction between manganese dioxide and hydrogen peroxide). It shows the gas pressure build up against time. What do I do to even start ...
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1
answer
121
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Retrosynthesis of saffron pyranone from acetone and acetic acid
I have an assignment on the retrosynthesis of a lactone (4,4,6‐trimethyloxan‐2‐one) from acetone and acetic acid as precursors:
And I came up with the following scheme:
I initially went for a 1,4-...
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27
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Calculating pH for Polyprotic Acids and Buffers
I’m trying to understand how to calculate pH for polyprotic acids in different scenarios, especially in relation to buffers, and I have a couple of questions:
When
pH≫pKa or pH≪pKa, should I calculate ...
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1
answer
60
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Excitation of electron when the next higher shell is full
Take $\ce{[Ne] 1s^2 2s^2 2p^6}$. If I input the $1$st excitation energy to the $1$st shell electron where will it go? And what would happen since the $2$nd shell is already filled?
For example I give $...
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1
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If AlCl3 has such a high lattice energy, why is it so soluble in organic solvents?
AlCl3 is well known to be relatively covalent, but doesn't solubility generally go down as lattice energy increases, (I.e born-haber cycle?)? However it's soluble in many organic solvents
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Removing Naphthalene Odor caused by Snake-B-Gon [closed]
How to remove naphthalene's odor. Spread snake-b-gon in our basement. Didn’t realize for outdoor use only. House is full of odor now.
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Feasibility of converting TiO₂ on titanium to BaTiO₃ in solution
I’m exploring the feasibility of transforming a TiO₂ layer (of varying thickness) on a titanium surface into BaTiO₃ stable layer by processing it in barium-ion-rich solutions. A specific reaction I’ve ...
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0
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44
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Why does sodium ethoxide solution in ethanol not self-E2?
If E2 reactions are favored by primary alcohols and strongly basic conditions, why does sodium ethoxide solution in ethanol not E2 itself to form ethylene?
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Cancelling terms in charge-balance equation
I am having problems in understanding which terms are significantly small and can be cancelled in ionic equilibrium-based expressions. Particularly, I faced this issue while applying charge balance ...
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3
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1
answer
36
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Estimating errors on negative mass spec intensities
I am writing mass spectrometry (specifically, residual gas analysis with a quadrupole mass spec) data reduction software and have come across an interesting problem.
My primary goal here is to ...
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0
answers
44
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Which is more electronegative, deuterium or hydrogen
There has not been a clear answer found so I am asking here - which is more electronegative or which would display a greater electronegativity in compounds H2O and D2O and why - deuterium or protium. ...
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64
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What are the explanations for some of the absurd implications of hybridisation? [closed]
While studying VBT there were some absurd implications of hybridisation I came across and could not explain using VBT, I came here to see if there is anyway to reconcile with these implications.
1)...
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22
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Detection of trace chemicals - textbook [duplicate]
I'm trying to do a literature review of all the methods that are there to detect specific organic molecules that are there at a 0.1-5% concentration in a mix of vapours with other organic molecules ...
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0
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17
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How to predict the time for hydride formation after knowing the initial and final concentration of hydrogen into hydride?
I was trying to do time based calculations in terms of predicting the amount of time it will take to form the first hydride ($\ce{LaNi5H6}$) once the hydrogen is pass through the metal($\ce{LaNi5}$), ...
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1
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Why don't similar locations of spectral lines produce similar "colors"?
Why don't similar locations of spectral lines produce similar "colors"?
See red arrows below showing different elements but similar locations but different "colors"
Edited image ...
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2
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58
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estimate specific heat and enthalpy based on chemical formula
Given the chemical formula of a coumpound (and possibly the arrangement of the various atoms and connections inside), are there theoretical or numerical approaches to compute the enthalpy and heat ...
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45
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Which is more soluble in water - Butan-1-ol or Butan-1amine? [duplicate]
While studying about the physical properties of amines, I came across a question -
Which is more soluble in water butan-1-ol or butan-1-amine?
If I think that butan-1-ol is more soluble in water, I ...
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32
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What exactly is the distillate produced when dehydrating 1,4 butaneidol [closed]
I am trying to synthesize gamma-butyrolactone from 1,4 butaneidol using sulfuric acid as a catalyst. From what I know all that needs to happen is I need to dehydrate 1,4 butaneidol using a simple ...
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Actives ph adjustments doubts
I hope someone can answer my question please.
Should I measure the pH value after each addition of active ingredients in my cosmetic formula to ensure that the active ingredient remains within its ...
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1
answer
48
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trying to the solve the equation for the metal hydride hydrogen compression from one of the research paper and understand the unit of the equations
The study of metal hydrides involves the storage of hydrogen in solid-state compounds, which is governed by thermodynamic principles. The Pressure-Concentration-Temperature (PCT) curve is crucial for ...
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1
answer
40
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Salt hydrolysis equilibrium
When we consider the hydrolysis of the anion of a weak acid (taken along with a strong base), we tend to calculate the pH, which is basically the hydrogen concentration, indirectly through the $\ce{[...
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Formation of Ketal with monohydric alcohol
Do ketones react with monohyric alcohol to form ketals?
Some books state "Ketones do not readily react with monohydric alcohols"
While some form ketals with monohydric alcohols.
Which one is ...
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45
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Math/Chemistry calculation (help with reasoning...)
I'm slightly confused about the reasoning behind a chemistry/math calculation, and I'll give this forum a try.
I have measured the "DPM" (disintegration per minute) from a sample. This is ...
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1
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44
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Coordination number of iron in ferrocene
Is coordination number of Iron in ferrocene 6 or 10?
6 because, there are 3 coordinate bonds from each cyclopentadienyl ring. And 10 because π-electron density is shared with 5 carbon atoms in each ...
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1
answer
34
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Enthalpy Change in Reversible Isothermal Process
This is with reference to the following question from JEE Advanced 2024 Paper 1 :
The solution to this is by taking $\pu{\Delta H = 0}$ in process XY due to it being isothermal, then applying $\pu{\...
