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The beryllium ion, $\ce{Be^{2+}}$, forms the aquo complex $\ce{[Be(H2O)4]^{2+}}$. According to [LibreTexts][1], this complex is acidic in solution: $$\ce{[Be(H2O)4]^{2+} + H2O -> [Be(H2O)3OH]+ + H3O+}$$
It is not clear to me why it should be acidic. I read [here][2] that "the hydrolysis happens because the $\ce{Be−O... |
I recently had an exam question, pictured below, regarding a Friedel-Crafts alkylation of benzene. The question wants to know what would form as the major product. My response was marked incorrect. I discussed the item with the professor, who told me that the correct answer was that more than one of the products would ... |
I recently had an exam question, pictured below, regarding a Friedel-Crafts alkylation of benzene. The question wants to know what would form as the major product. I responded that the second option, sec-butylbenzene, would form as the major product. This response was marked incorrect. I discussed the item with the pro... |
> What is meant by a "very strong" Be−O bond? If berylium's tendency to hold on to water ligands is unusually strong, is it due to its small ionic size?
You got that absolutely right.
$\ce{Be\bond{-}O}$ is a strong bond because of the small size of Be. **Smaller** cation size means a **stronger pull** on the $\ce{O... |
I have to do an experiment which involves getting the extract of certain leaves. I had decided to macerate it in ethanol (70%) solution and then to evaporate the solvent using water bath/rotary evaporator.
Due to the pandemic, I couldn't get access to labs to conduct this experiment. Is there any other way to evapor... |
Furfural $(\ce{C5H4O2})$ has been used as a feedstock for synthesis. Furfurylamine $(\ce{C5H7NO})$ is made from furfural.
Given that industrial manufacturing ammonia is matured, how about combining furfural, ammonia and hydrogen to directly synthesize pyridine? Is the following reaction realizable?
$$\ce{C5H4O2 +... |
What pressure does liquid nitrous oxide need at -45°C to remain liquid? How can I calculate it's pressure required for other temperatures? |
What pressure does liquid nitrous oxide need at -45°C? |
Hydrazine $\ce{N2H4}$ and dinitrogen tetroxide $\ce{N2O4}$ form a hypergolic fuel and oxidizer pair widely used in spacecraft including [Akatsuki](https://en.wikipedia.org/wiki/Akatsuki_(spacecraft)) (あかつき, 暁, "Dawn") also known as the Venus Climate Orbiter (VCO) and Planet-C.
Wikipedia [states](https://en.wikipedia... |
You should investigate several pH and study the effect of time on the fluorescence spectra. One cannot quote single values without mentioning the wavelengths of excitation and emission.
pH can alter the state of ionization and it can also cause hydrolysis of the sugar unit.
You need to collect three different t... |
You would expect solubility of Group $2$fluorides to increase down the group, as lattice energy plummets much more sharply than hydration energy does. For the most part, this is true: $\ce{BaF2}$ is more soluble than $\ce{SrF2}$, which is more soluble than $\ce{CaF2}$, and so on. However, [$\ce{BeF2}$][1] is several t... |
Why does beryllium have an exceptionally high hydration energy? |
You would expect solubility of Group $2$ fluorides to increase down the group, as lattice energy plummets much more sharply than hydration energy does. For the most part, this is true: $\ce{BaF2}$ is more soluble than $\ce{SrF2}$, which is more soluble than $\ce{CaF2}$, and so on. However, [$\ce{BeF2}$][1] is several ... |
What happens to viscosity at critical micelle concentration? Does it increase or decrease abruptly, and if so, what's the reason behind it?
I'm aware of changes in other properties such as conductivity, concentration etc, but not viscosity. |
What pressure does liquid nitrous oxide need at −45 °C to remain liquid? How can I calculate its pressure required for other temperatures? |
What pressure does liquid nitrous oxide need at −45 °C? |
You would expect solubility of Group $2$ fluorides to increase down the group, as lattice energy plummets much more sharply than hydration energy does. For the most part, this is true: $\ce{BaF2}$ is more soluble than $\ce{SrF2}$, which is more soluble than $\ce{CaF2}$, and so on. However, [$\ce{BeF2}$][1] is several ... |
The flame test colors for alkali metal and alkaline earth metal salts are well known, but what about the metals themselves? Do they also give rise to the same colors (eg, brick red for Ca, pale green for Ba etc), or does it differ? And if so, why? |
One of the sections about retrosynthesis in Warren's book addresses how to access $\gamma$-hydroxy carbonyl compounds like **ZM181**. This is again one of the examples to advice the reader to check the results for plausibility: while epoxides *often may* be a suitable building block, *here*, the intermediate would rea... |
H[AuCl4]: Is it *tetrachloroauric [III] acid* or *hydrogen tetrachloroaurate[III]* ? As per the rules I have studied the latter name is correct then why am I getting the former name mentioned everywhere on the internet as the iupac name although Wikipedia does mention the other name(hydrogen tetrachloroaurate[III]) tho... |
Free evaporation or using a water bath ?
Both ethanol and water evaporate at any temperature, just with the exponential-like rate. ( Washed clothes will dry up even at freezing temperatures ).
If living in area with currently cold weather, consider using evaporation on the central heating radiator, parhaps pa... |
Why transition metal chloride complex have lower reduction potential than metal aqua ions?
i.e.:
- Au3+(aq) + 3e- --> Au(s) E°= +1,52V
- AuCl4-(aq) + 3e- --> Au(s) + 4Cl- E°= +0,93V
Is it because the chloride complex formation constant is very high (higher than aqua ions') so the reduction of Au is less f... |
Why transition metal chloride complex have lower reduction potential than metal aqua ions? |
How to use anodic and cathodic overpotentials to calculate electrolytic energy efficiency? |
Why transition metal chloride complex have lower reduction potential than metal aqua ions?
i.e.:
- $\ce{Au^3+(aq) + 3e- -> Au(s)}$ $\mathrm{\,\,\,\,\,E°= +1.52V}$
- $\ce{AuCl4-(aq) + 3e- -> Au(s) + 4Cl-}$ $\mathrm{\,\,\,\,\,E°= +0.93V}$
Is it because the chloride complex formation constant is very high (h... |
Is $\ce{H[AuCl4]}$ **tetrachloroauric [III] acid** or **hydrogen tetrachloroaurate[III]**? As per the rules I have studied the latter name is correct. Then why am I getting the former name mentioned everywhere on the internet as the IUPAC name, although Wikipedia does mention the other name (hydrogen tetrachloroaurate[... |
The authoritative source [*Nomenclature of Inorganic Chemistry, IUPAC Recommendations 2005 (Red Book)*](https://iupac.org/what-we-do/books/redbook/) lists $\ce{H[AuCl4]}$ as an example of a *salt* in the subsection *IR-4.4.3.4 Generalized salt formulae* \[1, pp. 61–62\].
Further, introduction to the section *IR-8 In... |
I tried doing this problem, but I have some questions that are confusing me:
1) Do we assume this reaction goes to completion? $$\ce{KI + AgCl->KCl + AgI}$$
2) Is the $\pu{0.10M}$ $\ce{KI}$ unnecessary information? If yes, why do we not need it?
3) Should we setup equilibriums?
Overall, I'm just confused. ... |
> Calculate the concentration of $\ce{I−}$ in a solution obtained by shaking $\pu{0.10 M}$ $\ce{KI}$ with an excess of $\ce{AgCl(s)}.$
I tried doing this problem, but I have some questions that are confusing me:
1. Do we assume the following reaction goes to completion
$$\ce{KI + AgCl -> KCl + AgI}?$$
2. Is ... |
How does addition of AgCl affect concentration of iodide in KI solution? |
I was parsing the following post https://chemistry.stackexchange.com/questions/111109/what-is-the-maximum-number-of-emission-lines-when-the-excited-electron-of-a-h-at?newreg=83f7c7a33b8840ae85dfcc4d60aad126 and came across with the reply from @porphyrin.
cite : "lease note that these answers are only true in the Boh... |
Maximum number of Spectral Lines "A better quantum model shows that there will be n^2 transitions"? |
I was parsing the following post https://chemistry.stackexchange.com/questions/111109/what-is-the-maximum-number-of-emission-lines-when-the-excited-electron-of-a-h-at?newreg=83f7c7a33b8840ae85dfcc4d60aad126 and came across with the reply from @porphyrin.
cite : "lease note that these answers are only true in the Boh... |
How would you know when an acid or base is paired with $\ce{H2O}$ that it will form an $\ce{OH-}$ ion or a $\ce{H3O+}$ ion? I just started the acid and base equilibrium unit, and I'm just confused on what conditions $\ce{OH-}$ or $\ce{H3O+}$ ions form. |
How to know if a reaction forms $\ce{H3O+}$ ions or $\ce{OH-}$ ions? |
How to know if a reaction forms H3O+ ions or OH- ions? |
what is an organic compound that can meet these conditions? |
If we have a 1° halide that also contains a carbonyl group (like this one[![enter image description here][1]][1]), and we add 1 mole of KCN in DMSO to it, what will happen?
Will the $S_N2$ product by substuition of chlorine or Nucleophilic addition at the carbonyl carbon be the major product, and why?
[1]: ht... |
Does KCN prefer $S_N2$ or Nucleophilic addition? |
If we have a 1° halide that also contains a carbonyl group (like this one[![enter image description here][1]][1]), and we add 1 mole of KCN in DMSO to it, what will happen?
Will the $S_N2$ product by substuition of chlorine or Nucleophilic addition at the carbonyl carbon be the major product, and why? And does using... |
If we have a 1° halide that also contains a carbonyl group (like 5‐chloropentan‐2‐one), and we add 1 mole of KCN in DMSO to it, what will happen?
[![5‐chloropentan‐2‐one][1]][1]
Will the S<sub>N</sub>2 product by substitution of chlorine or nucleophilic addition at the carbonyl carbon be the major product, and wh... |
Does KCN prefer SN2 or nucleophilic addition? |
Chlorophyll as the main photoreceptor molecule in photosynthesis seems to have three unique features 1) a lot of conjugated double bonds, 2) a ring like structure and 3) a central metal ion (Mg). The conjugated double bonds make sense, as this creates delocalized electrons, resulting in excitation energies in the opti... |
$\ce{Br2-H2O}$, containing some $\ce{NaCl,AlCl3}$ ?
---
I initially though that there would be anti addition of Br and OH to give **3-Bromobutan-2-ol** but then I also got the intuition that NaCl might ionize in water and the $\ce{Cl-}$ might be involved here as well (obviously, with different stereochemical... |
How does $\ce{NaOH}$ form the following product? |
> [![2‐phenyl‐hexahydro‐2H‐pyrano\[3,2‐d\]\[1,3\]dioxin‐6‐ol to 3‐(5‐hydroxy‐2‐phenyl‐1,3‐dioxan‐4‐yl)propanal][1]][1]
I am given the molecule in black which is treated with $\ce{NaOH}$. The product is in blue.
Could someone explain the mechanism? All I have so far is that the $\ce{-OH}$ group on the bottom righ... |
How does NaOH modify pyranodioxins? |
Furfural $(\ce{C5H4O2})$ has been used as a feedstock for synthesis. Furfurylamine $(\ce{C5H7NO})$ is made from furfural.
Given that industrial manufacturing ammonia is matured, how about combining furfural, ammonia and hydrogen to directly synthesize pyridine? Is the following reaction realizable?
$$\ce{C5H4O2 +... |
What happens when tran-2-butene reacts with aqueous bromine in the presence of chloride? |
The answer to this question is actually pretty interesting, I think. @user55119 's comment that the principal chain is the cyclohexane ring is correct -- but it seems like you understand that that's what the teacher is saying, and you're asking, "why?" The best short answer, too, is imho in your comments: @MaxW 's "n... |
What does phase change from liquid to gas have to do with equality of vapor pressure and ambient pressure? I understand that at higher pressures more kinetic energy is needed for molecules in liquid to spread out to form bubbles of vapor since vapor has lower density than liquid which means that higher temperature is n... |
Why is Vapor Pressure of Liquid Equal to Ambient Pressure at Boiling? |
I discovered with litmus paper that magnesium ascorbate is acidic and, from https://foodb.ca/compounds/FDB015417, that potassium acetate should also be acidic.
How can this be? Shouldn’t the weak acid conjugate bases, ascorbate and acetate, be basic and the strong dissociated ions, K+ and Mg2+, neutral? |
Why are magnesium ascorbate and potassium acetate, which are salts of strong bases with weak acids, acidic? |
If you reacted TsOH with a secondary or tertiary alcohol, will you ever see a racemic mixture of OTs substituted products after the water group leaves? Is OTs just too weak of a nucleophile to ever substitute? |
Will OTs ever act as a nucleophile and substitute with an alcohol? |
Why are magnesium ascorbate and potassium acetate, which are salts of strong bases with weak acids, acidic?
I discovered with litmus paper that magnesium ascorbate is acidic and, found out from https://foodb.ca/compounds/FDB015417 that potassium acetate should also be acidic.
How can this be? Shouldn’t conjugate ... |
Why is magnesium ascorbate, which is a conjugate base of a weak acid, acidic? |
Usually, strong acid anions and strong base cations don't get hydrolysed. But I've noticed through some questions that $\ce{Ag^+}$ doesn't seem to get hydrolysed, why is that? Is there any concept that I'm not aware of that predicts which ions get hydrolysed and which don't, or is it just the ions from strong acids/bas... |
Why is Ag+ not hydrolysed? |
This question is primarily based on the Cannizzaro reaction, where a base induces a disproportionation reaction of non-enolizable aldehydes (benzaldehyde, formaldehyde) to form an alcohol and a carboxylic acid.
In the video by Nile Red exploring the Cannizzaro reaction (https://www.youtube.com/watch?v=qEBC204WTKs), ... |
Why transition metal chloride complex have lower reduction potential than metal aqua ions?
i.e.:
- $\ce{Au^3+(aq) + 3e- -> Au(s)}$ $\mathrm{\,\,\,\,\,E^\circ} = +\pu{1.52 V}$
- $\ce{[AuCl4]-(aq) + 3e- -> Au(s) + 4Cl-}$ $\mathrm{\,\,\,\,\,E^\circ} = +\pu{0.93 V}$
Is it because the chloride complex formatio... |
Why transition metal chloride complex have lower reduction potential than metal aqua ions? For example:
$$
\begin{align}
\ce{Au^3+(aq) + 3 e- &-> Au(s)} &\quad E^\circ &= \pu{+1.52 V}\tag{1}\\
\ce{[AuCl4]-(aq) + 3 e- &-> Au(s) + 4 Cl-} &\quad E^\circ &= \pu{+0.93 V}\tag{2}
\end{align}
$$
Is it because the ch... |
In cases where a metal ion like, Fe(III), Cr(III), Pt(II) is made to react with a ligand species like oxalate, CN-, CO etc and it forms a complex then, How do we determine whether 6 ligands will be coordinated to the central atom(i.e. in case of octahedral) or 4 ligands will be coordinated (as in tetrahedral or square ... |
Octahedral, Tetrahedral or Square planar? |
One of the more fundamental theories of solution viscosity (by Einstein) predicts the following for dilute solutions of perfect spheres in a Newtonian fluid:
$$\frac{\eta}{\eta_0} = 1 +2.5\phi \tag{1}$$
where $\eta_0$ is the viscosity of the pure solvent, $\phi$ is the volume fraction of solute (here: aggregatin... |
The anion $\ce{AuCl4−}$ is the most known complex of gold(III). It is very stable complex and have very high formation constant ($K_f$). That is the reason the metal chloride complex have a lower reduction potential than metal aqua ion. As pointed out in the other answer, this is a consequence of Nernst's law. ... |
This question is primarily based on the Cannizzaro reaction, where a base induces a disproportionation reaction of non-enolizable aldehydes (benzaldehyde, formaldehyde, etc) to form an alcohol and a carboxylic acid.
In the video by Nile Red exploring the Cannizzaro reaction (https://www.youtube.com/watch?v=qEBC204WT... |
Cast iron pans are a traditional cooking utensil and are becoming more and more popular in recent years.
I myself switched from Teflon/ PFC pans to cast iron pans.
To use the pan they are normally coated with oil, which is baked in. For this mostly line seed oil is used, as it polymerizes well.
The normal proce... |
I am currently working on a lab, where I am trying to calculate whether the R group in penicillin type drugs has an affect on the ring strain of the beta lactam. I know how to find ring strain in cycloalkanes through the molar heat of combustion, however I can't find any information about the combustion of beta lactams... |
How can you calculate ring strain in beta lactams for different penicillin drugs? |
Cast iron pans are a traditional cooking utensil and are becoming more and more popular in recent years.
I myself switched from Teflon/ PFC pans to cast iron pans.
To use the pan they are normally coated with oil, which is baked in. For this mostly line seed oil is used, as it polymerizes well.
The normal proce... |
So I was comparing the $+M$ effect of $CH_2^-$,$NH_2^-$ and $O^-$. Answer was given as:
$$ CH_2^- > NH_2^- > O^- $$
So, I attach them with ethene and made their respective resonating structures as:
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/s6Ojv.jpg
So my doubt was whether $b... |
So I was comparing the $+M$ effect of $\ce{CH^-_2}$, $\ce{NH^-_2}$ and $\ce{O^-}$. Answer was given as:
$$ \ce{CH^-2 > NH^-_2 > O^-}$$
So, I attach them with ethene and made their respective resonating structures as:
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/s6Ojv.jpg
So ... |
Sublimation is defined by the [IUPAC](https://goldbook.iupac.org/terms/view/S06069) as *The direct transition of a solid to a vapour without passing through a liquid phase*.
A sublimation equilibrium can occur in two sets of conditions:
- at a temperature-pressure set given by the phase diagram of the pure substanc... |
What is the difference between sublimation and instantaneous fusion+vaporisation? |
One of the more fundamental theories of solution viscosity (by Einstein) predicts the following for dilute solutions of perfect spheres in a Newtonian fluid:
$$\frac{\eta}{\eta_0} = 1 +2.5\phi \tag{1}$$
where $\eta_0$ is the viscosity of the pure solvent, $\phi$ is the volume fraction of solute (here: aggregatin... |
While [this question has been asked and answered](https://chemistry.stackexchange.com/q/69822/101483), it may indicate that a column chromatography **qualitatively** is possible. At home, is it possible after collecting **silica gel**s from small bags of them from snack packages? Secondly, if qualitative analysis is po... |
Can I use silica gel to perform column chromatography at home? |
I made an experiment where I made a Friedel-Crafts acetylation of ferrocene. Now I would like to know if/how I can distingusih ferrocene, acetylferrocene and diacetylferrocene in a NMR spektra? For my reaction I used ferrocene, acetic anhydride and phosphoric acid. |
How do you distinguish ferrocene, acetylferrocene and diacetylferrocene in a NMR spektra? |
Fundamentals of Analytical Chemistry book states that the plate height can be thought of as the length of column that contains a fraction of the analyte that lies between $L$ and $L - \sigma$.
But what I know is that $H = \sigma^2 / L$ (At the retention time), so, how can plate height be equa... |
How the plate height is assumed to be the standard deviation? |
Fundamentals of Analytical Chemistry book states that the plate height can be thought of as the length of column that contains a fraction of the analyte that lies between $L$ and $L - \sigma$.
But what I know is that $H = \sigma^2 / L$ (At the retention time), so, how can plate height be equa... |
*Fundamentals of Analytical Chemistry* book states that the plate height can be thought of as the length of column that contains a fraction of the analyte that lies between $L$ and $L - \sigma$ \[1, p. 870\].
But what I know is that $H = \sigma^2 / L$ (At the retention time), so, how can plat... |
# Software
- [ChemOffice Professional](http://www.cambridgesoft.com/Ensemble_for_Chemistry/ChemOffice/ChemOfficeProfessional/)
**Commercial software** for drawing molecular structures, 3D models and many more. High price but most higher education institutes will provide students/staff with free institutional l... |
While [this question has been asked and answered](https://chemistry.stackexchange.com/q/69822/101483), it may indicate that a column chromatography **qualitatively** is possible. **At home**, is it possible after collecting **silica gel**s from small bags of them from snack packages? Secondly, if qualitative analysis i... |
I feel that you misunderstood what the authors were trying to say in that textbook. Forget about everything for the time being.
Imagine if you injected a single analyte band into an HPLC column of length L at a constant flow rate. You waited for some time, and now the band is exiting the column. For simplicity, assume... |
does anyone know where can I find the critical temperature and critical pressure condition data of Starch (Corn)? |
I am doing polarization calculations to get data for use in other calculations. To start with, I want to calculate the static dielectric constant. However, I'm a newbie to polarization and it is a struggle to relate my calculation output to the static dielectric constant. If someone could point me in the right directi... |
Does anyone know what program was used to make this molecular structure picture? |
How do you distinguish ferrocene, acetylferrocene and diacetylferrocene in a NMR spectra? |
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 reaction I used ferrocene, acetic anhydride and phosphoric acid. |
I am doing polarization calculations to get data for use in other calculations. To start with, I want to calculate the static dielectric constant. However, I'm a newbie to polarization and it is a struggle to relate my calculation output to the static dielectric constant. If someone could point me in the right directi... |
`Can a spark ignite hydrogen? Also, what about the tip of a cigarette?`
Yes, if the $\ce{H2(g)}$ concentration in oxygen or air is greater than about 4% not only will it burn, but most likely explode. You should avoid all heat sources when dealing with it, including direct sunlight. Just so you know, hydrogen safety... |
Is 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 of existence of a triple point in such a case?
Also, since the vapour equilibrium curve ends at point E , what is the... |
Is 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 of existence of a triple point in such a case?
Also, can there be multiple triple points for a compound?
Also, since... |
Glycinate as far as I can guess from the structure is a mono anion with negative charge on oxygen atom(though that negative charge is resonating). But when I used this logic in my exam it costed me 4 marks. I don't understand why. Is it because it is derived from glycine in strongly basic medium which is not a mono ani... |
is Glycinate ligand a mono anion or a zwitterion? |
In general, fluoride ion affinity, ammonia binding energy, photoacoustic IR spectra of adsorbed species (pyridine, CO) are used to measure the Lewis acidity of a material.
But in the **computer simulation method**, such methods are not suitable to calculate nanoclusters Lewis acidity because of the susceptible elect... |
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