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Can eggs boil indefinitely? |
A double bond between 2 carbon atoms means there is a $\pi$ bond with the side orbital overlaps in 1 plane, in parallel to the axial $\sigma$ bond.
The consequence is, eventual rotation would break this $\pi$ bond, making the double bond just a single bond.
Breaking double bonds by rotation requires a strong torqu... |
A double bond between 2 carbon atoms means there is a $\pi$ bond with the side orbital overlaps in 1 plane, in parallel to the axial $\sigma$ bond.
The consequence is, free rotation would need to break this $\pi$ bond, making the double bond just a single bond, what would require a strong torque and a lot of energy.... |
I need to retro-synthetically design a valid synthesis plan (in two steps, from cheap starting materials available over at Sigma Aldrich) for a target compound, pictured below.
[![2-[(E)-2-(3-bromophenyl)ethenyl]-1,3-benzoxazole][1]][1]
How would I go about doing this?
[1]: https://i.stack.imgur.com/PXRi7.... |
How to develop a retrosynthesis plan for 2-[(E)-2-(3-bromophenyl)ethenyl]-1,3-benzoxazole? |
> The alkyl chains of saturated fat molecules can readily rotate about
> their carbon-carbon single bonds, giving them flexibility and
> viscosity.
What is different about the carbon-carbon double bonds of unsaturated fat molecules, preventing interconversion of cis and trans forms? |
> The alkyl chains of saturated fat molecules can readily rotate about their carbon-carbon single bonds, giving them flexibility and viscosity.
What is different about the carbon-carbon double bonds of unsaturated fat molecules, preventing inter-conversion of cis and trans forms? |
Why can't C-C double bonds rotate? |
My textbook quotes the following as the limitation of Ellingham diagram:
>The interpretation of $\Delta G_\mathrm{f}^\circ$(standard Gibbs free energy of formation) is based on $K$ ($\Delta G_\mathrm{f}^\circ = -RT \ln K$).Thus it is presumed that the reactants and products are in equilibrium.
Definition of Stand... |
How can Ellingham diagrams be linked to Gibbs energies of formation? |
A double bond between 2 carbon atoms means there is a $\pi$ bond with the side orbital overlaps in 1 plane, in parallel to the axial $\sigma$ bond.
The consequence is, free rotation would need to break this $\pi$ bond, making the double bond just a single bond, what would require a strong torque and a lot of energy.... |
Is dialkyldimethylammonium chloride suitable for sterilization in mycology? |
In hobby-mycology 70% rubbing alcohol is commonly used for sterilizing work surfaces, bags, syringes, still air boxes, basically everything.
Alcohol however, seems to have some downsides, when it comes to mycology as it needs a long soak time to actually kill anything and it doesn't kill mold and mold spores at all,... |
see frame-shortening effects on electrostatic forces/van der waals at the edges, or are molecules too weak or necessarily neutral to be manipulated this way? |
This question has gave me headaches so far due the problematic nature of how to get to the equation for finding the pH of the resulting solution from such salt.
Can someone help me with this?
The problem is as follows:
> Find the pH of a solution of $NH_{4}CN$ $1\,M$. Their respective
> hydrolisis constants a... |
Which method is more accurate to calculate the pH of a salt from a weak acid and weak base and how to prove it? |
What Textbook states about the formation of electric double layer:
>When silver nitrate solution is added to potassium iodide solution the precipitated silver iodide adsorbs iodide ion from dispersion medium and negatively charged colloidal sol results.Having accuquired a negative charge by selective adsorption on t... |
Is this step justified? |
Can someone help me with this?
The problem is as follows:
> Find the pH of a solution of $\ce{NH4CN}$ $\pu{1M}$. Their respective
> hydrolysis constants are:
>
> $K_h=\pu{5.6\times 10^{-10}}$
>
> $K_h=\pu{2.5 \times 2.5 \times 10^{-5}}$
The alternatives given are as follows:
$\begin{array}{ll}
1.&2.... |
Can someone help me with this?
The problem is as follows:
> Find the $\mathrm{pH}$ of $\pu{1M}$ solution of $\ce{NH4CN}$. Their respective
> hydrolysis constants are:
>
> $K_h = 5.6\times 10^{-10}$
>
> $K_h = 2.5 \times 2.5 \times 10^{-5}$
The alternatives given are as follows:
$\begin{array}{ll}
1.... |
Also, is it possible to see frame-shortening effects on electrostatic forces/van der waals at the edges, or are molecules too weak or necessarily neutral to be manipulated this way? |
Is it possible to hold and rotate molecules to relativistic speeds around axis in observable way? |
A double bond between 2 carbon atoms means there is a $\pi$ bond with the side orbital overlaps in 1 plane, in parallel to the axial $\sigma$ bond.
The consequence is, free rotation would need to break this $\pi$ bond, making the double bond just a single bond, what would require a strong torque and a lot of energ... |
This is a question from JEE Advanced 2019 ( a highly valued engineering entrance exam in India) but the fact that we are ignoring basic rules of electrophilic substitution is disturbing. Correct me if I am wrong or missing something really important, but according to synergic electrophilic substitution it should be an... |
I do recall researching on what can cause storage bottles to fail with age, and my recollection included the obvious (like the chemical nature of what is being stored, heating as your shed is likely not air-conditioned and the action of direct or diffused sunlight) together with other things I would not have expected.
... |
> In the reaction involving $\pu{124 g}$ of aluminium and $\pu{601g}$ iron (III) oxide, what is the amount of substance in moles of the limiting reagent?
Here is what I have so far:
Balanced equation:
$$\ce{2Al + Fe2O3 -> Al2O3 + 2Fe}$$
$\ce{Al}$ has MW = $27$, mass = $\pu{124 g}$ and determined its amount us... |
What is the amount of limiting reagent in this chemical reaction? |
This is a question from JEE Advanced 2019 (a highly valued engineering entrance exam in India), but the fact that we are ignoring basic rules of electrophilic substitution is disturbing. Correct me if I am wrong or missing something really important, but according to synergic electrophilic substitution, it should be a... |
Diphenylcarbazide is used in test strips for heavy metals detection in drinking water but I can't find much info on this reagent, apart from it's MSDS and a preparation for detecting Chromium VI ions, in which diphenylcarbazide 250 mg is dissolved in 50ml acetone and few drops added to test sol which is then mixed with... |
How diphenylcarbazide is used to detect Mercury II ions? |
Can someone help me with this?
The problem is as follows:
> Find the $\mathrm{pH}$ of $\pu{1M}$ solution of $\ce{NH4CN}$. Their respective
> hydrolysis constants are:
>
> $K_h = 5.6\times 10^{-10}$
>
> $K_h = 2.5 \times 10^{-5}$
The alternatives given are as follows:
$\begin{array}{ll}
1.&2.8\\
2.&... |
The Diphenylcarbazide Test for the presence of mercury was used as early as 1920s. However, since the test is very delicate (the test can detect $\pu{250 \mu g/L}$ mercury in solution), it has been used predominantly in neutral solutions, until it have been adapted to Quantitative Analysis Scheme by Scott in 1929 (Ref.... |
On the Medical Sciences StackExchange site I asked [Can a calorie be neither protein, carb, nor fat?
](https://medicalsciences.stackexchange.com/questions/20894/can-a-calorie-be-neither-protein-carb-nor-fat) and got a very helpful answer, which was that ethanol (in alcoholic drinks) is caloric but neither a protein, n... |
What substances do humans consume that are caloric but neither protein, carb, nor fat? |
On the Medical Sciences StackExchange site I asked [Can a calorie be neither protein, carb, nor fat?
](https://medicalsciences.stackexchange.com/questions/20894/can-a-calorie-be-neither-protein-carb-nor-fat) and got a very helpful answer, which was that ethanol (in alcoholic drinks) is caloric but neither a protein, n... |
If you go to https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CONSLEG:1990L0i496:20081211:EN:PDF, you will see a fairly extensive list of caloric compounds (screenshot pasted below). This list is probalby not comprehensive -- likely there are many compounds we (which includes our gut bacteria) can metabolize for... |
If you go to https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CONSLEG:1990L0i496:20081211:EN:PDF, you will see a fairly extensive list of caloric compounds (screenshot pasted below). This list is probably not comprehensive -- likely there are many compounds we (which includes our gut bacteria) can metabolize for... |
If you go to https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CONSLEG:1990L0i496:20081211:EN:PDF, you will see a fairly extensive list of caloric compounds (screenshot pasted below). This list is probably not comprehensive -- likely there are many compounds we (which includes our gut bacteria) can metabolize for... |
It is known that order of reactivity of carbonyl derivatives towards nucleophiles follow the order as:
>Acyl halide> acid anhydride>ester> amide> amide derivatives
(**Source**: "A Guidebook to Mechanism in Organic Chemistry" by Peter Sykes M.Sc., PhD., F.R.S.C., C.Chm. Fellow and Vice-Master, Christ’s College, C... |
If you go to https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CONSLEG:1990L0i496:20081211:EN:PDF, you will see a fairly extensive list of caloric compounds (screenshot pasted below). This list is probably not comprehensive -- likely there are many compounds we (which includes our gut bacteria) can metabolize for... |
If you go to https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CONSLEG:1990L0i496:20081211:EN:PDF, you will see a fairly extensive list of caloric compounds (screenshot pasted below). This list is probably not comprehensive -- likely there are many compounds we (which includes our gut bacteria) can metabolize for... |
Synthesis routes
From molbase[dot]com :
Phenylhydrazine + urea -> 1,5-Diphenylcarbazide ~96% yield
Pasha; Madhusudana Reddy Synthetic Communications, 2009 , vol. 39, # 16 p. 2928 - 2934
Phenylhydrazine + urethane -> 1,5-Diphenylcarbazide + 1-Phenylsemicarbazide + Ammonia
Journal of the Chemical S... |
What happens if you’re mixing concrete and you add some lye to it? Does it make it weaker, stronger or does nothing at all? I’m guessing concrete is basic so adding lye to it might expedite the reaction, causing it harden faster? Alternatively, it may react to with the water and starve the mixture? |
What happens to concrete if you add lye to the mix? |
I already know that nitrogen triple bond requires a lot of energy to be broken so the activation energy is very high but the book also lists the endothermic energy change as a reason. Does it have something to do with the reaction also not being spontaneous due to the positive enthalpy change and thus positive free ene... |
Actually, here is a modification of your procedure involving some advanced radical chemistry with sulfur (see [Scheme 1 graphics and pages 6 to 7](https://pdfs.semanticscholar.org/533e/9a0b2e5d938abc555e267f2f9b1a6a29f720.pdf)) and the use of a photocatalyst with sunlight and oxygen from air.
My scheme is to burn a ... |
Actually, here is a modification of your procedure involving some advanced radical chemistry with sulfur (see [Scheme 1 graphics and pages 6 to 7](https://pdfs.semanticscholar.org/533e/9a0b2e5d938abc555e267f2f9b1a6a29f720.pdf)) and the use of a photocatalyst with sunlight and oxygen from air.
My scheme is to burn a ... |
From [Wikipedia](https://en.wikipedia.org/wiki/Lucas%27_reagent):
> The Lucas test in alcohols is a test to differentiate between primary, secondary, and tertiary alcohols. It is based on the difference in reactivity of the three classes of alcohols with hydrogen halides via an $S_N1$ reaction:
> $$ROH + HCl → RCl ... |
False positive in lucas test for primary alcohol due to formation of tertiary carbocation by rearrangement? |
Actually, here is a modification of your procedure involving some advanced radical chemistry with sulfur (see [Scheme 1 graphics and pages 6 to 7](https://pdfs.semanticscholar.org/533e/9a0b2e5d938abc555e267f2f9b1a6a29f720.pdf)) and the use of a photocatalyst with sunlight and oxygen from air.
My scheme is to burn a ... |
The Diphenylcarbazide Test for the presence of mercury was used as early as 1920s. However, since the test is very delicate (the test can detect $\pu{250 \mu g/L}$ mercury in solution), it has been used predominantly in neutral solutions, until it have been adapted to Quantitative Analysis Scheme by Scott in 1929 (Ref.... |
From [Wikipedia](https://en.wikipedia.org/wiki/Lucas%27_reagent):
> The Lucas test in alcohols is a test to differentiate between primary, secondary, and tertiary alcohols. It is based on the differences in reactivity of the three classes of alcohols with hydrogen halides via an $\mathrm{S_N1}$ reaction:
> $$\ce{RO... |
Hydrochloric Acid
H-Cl reacts in the same way, although often Zinc (II) chloride (a Lewis acid) is added to help compensate for the
lower nucleophilicity of chloride ion.
The mixture of HCl and ZnCl2 is called the Lucas Reagent.
Secondary and tertiary alcohols react via the SN1 mechanism with the Lucas reagent.
T... |
For my investigation, I am looking at the antioxidant levels of different types of tea. How could I compare the antioxidating ability of each tea?
For example, I know there is a method calling for DPPH radical and absolute ethanol, which I do not have at my disposal. Do you know any other method I could use? |
Is there any way of testing antioxidant ability of different substances? |
I already know that nitrogen's triple bond requires a lot of energy to be broken, so the activation energy is very high, but the book also lists the endothermic energy change as a reason.
1. Does it have something to do with the reaction also not being spontaneous due to the positive enthalpy change and thus positi... |
Why doesnt nitrogen react with oxygen at room temperature? |
Why doesn't nitrogen react with oxygen at room temperature? |
For example if $H_2$ is converted to $2H$, does the volume of the mixture change.
If it doesn't, does it imply that the work done is $0$ because work is $P \cdot dV$? |
Does dissociation of molecules into atoms change the volume of mixture? |
I have a big problem trying to wrap my head around this for several hours and I cannot seem to make sense of it.
I have to link this scheme with the 3 colored potential profiles on the bottom of the picture. Considering the electrolyte AK, which splits into A- and K+, that it is 10x more concentrated in compartment I ... |
A double bond between 2 carbon atoms means there is a $\pi$ bond with the side orbital overlaps in 1 plane, in parallel to the axial $\sigma$ bond.
The consequence is, free rotation would need to break this $\pi$ bond, making the double bond just a single bond, what would require a strong torque and a lot of energ... |
For example, if $\ce{H2}$ is converted to two $\ce{H},$ does the volume of the mixture change?
If it doesn't, does it imply that the work done is $0$ because work is $P\,\mathrm dV?$ |
I've searched low and high on the internet, but nothing to help me.
I know that Zinc is oxidised in preference to Iron, and that it "donates" those 2 electrons to iron.
$$\ce{Zn -> Zn2+ + 2e-}$$
But how does iron make use of those two electrons to revert back to iron when it turns into iron oxide, like so:
$$... |
How does Fe2+ become Fe in sacrificial protection? |
thanks for reading this, I have a question I hope you can answer. Formic acid is used as a coagulant to turn rubber tree sap into Latex, Formic acid also decomposes to Carbon Monoxide, does this mean things like Latex mattresses have the potential to off gas carbon monoxide? I am assuming they don't and this is a stupi... |
Formic acid, carbon monoxide off gassing in latex mattress? |
Why does every element have unique spectral lines?
I have studied that spectral lines help us to identify the properties of an element. This is because after excitation when the excited electron(s) fall back to their original energy level(s), photons of certain frequency corresponding to the difference between the ... |
Formic acid is used as a coagulant to turn rubber tree sap into Latex, Formic acid also decomposes to Carbon Monoxide, does this mean things like Latex mattresses have the potential to off-gas carbon monoxide? I am assuming they don't and this is a stupid question, but I have had carbon monoxide poisoning twice, I woul... |
Formic acid is used as a coagulant to turn rubber tree sap into latex, formic acid also decomposes to carbon monoxide. Does this mean things like latex mattresses have the potential to off-gas carbon monoxide? I am assuming they don't, but I have had carbon monoxide poisoning twice, so I would like to buy a latex mattr... |
I've searched low and high on the internet, but nothing to help me.
I know that Zinc is oxidised in preference to Iron, and that it "donates" those 2 electrons to iron.
$$\ce{Zn -> Zn2+ + 2e-}$$
But how does iron make use of those two electrons to revert back to iron when it turns into iron oxide, like so:
$$... |
I've searched low and high on the internet, but nothing to help me.
I know that zinc is oxidised in preference to iron, and that it "donates" those two electrons to iron.
$$\ce{Zn -> Zn^2+ + 2e-}$$
But how does iron make use of those two electrons to revert back to iron when it turns into iron oxide, like so:
... |
Hydrochloric Acid
$\ce{HCl}$ reacts in the same way, although often Zinc (II) chloride (a Lewis acid) is added to help compensate for the
lower nucleophilicity of chloride ion.
The mixture of $\ce{HCl}$ and $\ce{ZnCl2}$ is called the Lucas Reagent.
Secondary and tertiary alcohols react via the SN1 mechanism wi... |
Hydrochloric Acid ($\ce{HCl}$) reacts in the same way, although often Zinc (II) chloride (a Lewis acid) is added to help compensate for the lower nucleophilicity of chloride ion.
The mixture of $\ce{HCl}$ and $\ce{ZnCl2}$ is called the Lucas Reagent.
Secondary and tertiary alcohols react via the $\mathrm{S_N1}$ m... |
It is a common textbook question to treat the root mean square velocities of an ideal gas as given by the following equation: $v_{rms}=\sqrt{\frac{3RT}{M}}$. I was wondering about the validity of this equation, particularly as it applies to gases that are not monatomic. For example, in the following question from Zumda... |
According to KMT, is the velocity of an ideal gas always sqrt(3RT/M)? |
I am currently studying the textbook, *Mass Spectrometry*, third edition, by Jürgen H. Gross. Chapter **2.4.3 Bond Dissociation Energies and Heats of Formation** says the following:
> Great efforts have been made to generate accurate and reliable ion thermochemistry data. Once such data is available, it can be emplo... |
We have been told in lectures that the rate of radiationless transitions such as internal conversion and intersystem crossing decrease with the size of the energy gap between the states.
What is the explanation for this, in particular how does it involve the franck-condon factors between the two states? |
What is the explanation of the energy gap law in radiationless transitions? |
If you go to https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:01990L0496-20081211&qid=1580028914722&from=EN you will see a fairly extensive list of caloric compounds (screenshot pasted below). This list is probably not comprehensive -- likely there are many compounds we (which includes our gut bacteria) c... |
Too much confusion. Please bear with me.
[![enter image description here][1]][1]
**Source:
Jonathan Clayden, Nick Greeves, Stuart Warren, Organic Chemistry 2th Edition, 339.**
The general idea I got so far, is that, carbocation will be more stable if the + charge at central C is dispersed.
How can a very e... |
Why O and N promote SN1 but C=O inhibit SN1 although both are electron-withdrawing? |
It is a common textbook question to treat the root mean square velocities of an ideal gas as given by the following equation:
$$v_{rms}=\sqrt{\frac{3RT}{M}}$$
I was wondering about the validity of this equation, particularly as it applies to gases that are not monatomic. For example, in the following question from ... |
I already know that nitrogen's triple bond requires a lot of energy to be broken, so the activation energy is very high, but the book also lists the endothermic energy change as a reason.
1. Does the positive enthalpy change have something to do with the reaction not being spontaneous i.e. due to positive free ener... |
For a particular reaction can
Kc be equal to 1?
My confusion arised when I was studying effect of temperature on Kc.I see that the temperature must affect forward and backward rate constant differently for a reaction so that it changes Kc (which is ratio of the two rate constant).So i thought for a reaction with Kc e... |
Can rate constant for forward reaction be equal to rate constant for backward reaction? |
For a particular reaction can
Kc be equal to 1?
My confusion arised when I was studying effect of temperature on Kc.I see that the temperature must affect forward and backward rate constant differently for a reaction so that it changes Kc (which is ratio of the two rate constant).So i thought for a reaction with Kc e... |
For a particular reaction, can we have
$K_c = 1$?
My confusion arised when I was studying the effect of temperature on $K_c$ . I see that the temperature must affect forward and backward rate constants, differently for a reaction so that it changes $K_c$ (which is ratio of the two rate constants). So I thought for ... |
To the best of my knowledge, the effective nuclear charge $Z_\mathrm{eff}$ is usually defined such that the potential energy of an electron in an atom, $\langle V \rangle$, can be expressed as
$$\langle V \rangle =
-Z_\mathrm{eff}\langle\psi|\frac{1}{|r - r_a|}|\psi\rangle$$
The Hartree-Fock expression for $... |
> Is the effective nuclear charge just a semiempirical value fitted to approximate the total potential energy of an electron in an orbital, or is there another meaning behind the number?
No, that's pretty much it. The [Wikipedia entry][1] has a partial periodic table with some $Z_\mathrm{eff}$ values. If you go furt... |
I am not sure what is confusing the original poster. The comments were clear and the answer by Jan is clear. Let's try to walk you through the problem again.
The question asks about how many milligrams are there in $\pu{1 mM}$ caffeine solution. Did you attempt a dimensional analysis?
For mass to mole conversions... |
I am designing a machine that uses paper-thin sheets of silver. I am trying to find a material that can cover the silver to prevent it from tarnishing over time. Perhaps aerogel can work? |
Is there any material that can prevent silver from tarnishing? |
I desire to learn How does levomenthol allegedly superior to Menthol as pain killer in humans.
I didn't find a wiki article about levomenthol and the article [Menthol][1] doesn't mention this molecule.
The chemical formulas are the same but I understand that the only difference is spatial position of chemical bon... |
Does levomenthol superior to Menthol as pain killer in humans and what are the ways to determine this? |
I cannot fix the names and structures of the seven crystal systems in my head. There's a thousand books explaining their geometry and it's totally fine and understandable, no problem. But what do the names *mean*, etymologically?
1. Cubic
2. Tetragonal
3. Orthorhombic
4. Monoclinic
5. Hexagonal
6. Rhombohedral... |
From [Wikipedia](https://en.wikipedia.org/wiki/Lucas%27_reagent):
> The Lucas test in alcohols is a test to differentiate between primary, secondary, and tertiary alcohols. It is based on the differences in reactivity of the three classes of alcohols with hydrogen halides via an $\mathrm{S_N1}$ reaction:
> $$\ce{RO... |
The price differences between home testing kits to test tap-water for lead are huge.
20 dollar will either [buy 1 test][1] kit or [100 test strips][2]. Both are intended to test drinking-water safety.
What does this mean? Is one of the tests 100 times less sensitive? Or 100 times less accurate?
How can i as an av... |
What causes the differences in price in home testing kits for lead in water? |
A saturated solution is a solution that contains the max amount of solute able to be dissolved. However, can't a solution still be at equilibrium if you add more solute to a saturated solution as long as it doesn't reach supersaturation? What exactly is the requirement (in terms of saturation) for a reaction to be at e... |
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