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Which reacts better in a Cannizzaro Reaction ?
a) OHC-Ph-NO2
b) OHC-Ph-OCH3
A better hydride releasing group will be a better reactant, obviously. Therefore my answer was b, as -OCH3 shows -I(inductive) as well as -R(resonance), as its in para position. This increases the e- concentration in the C of CHO and d... |
Which reacts better in a Cannizzaro Reaction? |
> What is the amount of nitrate ions in $20.0\:\mathrm{g}$ of $\ce{Fe(NO_3)_3}$?
The chemical formula for the nitrate ion is $\ce{NO_3}$, I think.
The molar mass of $\ce{Fe(NO_3)_3}$ is $242~\mathrm{g~mol^{-1}}$ of which $186$ belong to $\ce{NO_3}$. That means that around $76.85\:\%$ of the substance is nitrate i... |
Which reacts better in a Cannizzaro Reaction?
a) OHC-Ph-NO2
b) OHC-Ph-OCH3
A better hydride releasing group will be a better reactant, obviously. Therefore my answer was b, as -OCH3 shows -I (inductive) as well as -R (resonance), as its in para position. This increases the e- concentration in the C of CHO and ... |
Which reacts better in a Cannizzaro Reaction?
a) $\ce{OHC-Ph-NO2}$
b) $\ce{OHC-Ph-OCH3}$
A better hydride releasing group will be a better reactant, obviously. Therefore my answer was **b**, as $\ce{-OCH3}$ shows -I (inductive) as well as -R (resonance), as its in para position. This increases the $e^-$ concen... |
Which reacts better in a Cannizzaro Reaction?
a) $\ce{OHC-Ph-NO2}$
b) $\ce{OHC-Ph-OCH3}$
A better hydride releasing group will be a better reactant, obviously. Therefore my answer was **b**, as $\ce{-OCH3}$ shows -I (inductive) as well as -R (resonance), as its in para position. This increases the $e^-$ concen... |
What is the amount of nitrate ions in 20 g of Fe(NO3)3? |
As I’m reading about water cations and anions, I read that the benefits we gain from water are of course lots, but the most important of them is the neutralisation of acids ($\ce{H+}$) from the anions present in water such as: $\ce{HCO3-}$ , $\ce{CO3^{2-}}$ and $\ce{OH-}$.
Does this mean that the higher the conc... |
As I’m reading about water cations and anions, I read that the benefits we gain from water are of course lots, but the most important of them is the neutralisation of acids ($\ce{H+}$) from the anions present in water such as: $\ce{HCO3-}$ , $\ce{CO3^2-}$ and $\ce{OH-}$.
Does this mean that the higher the concen... |
Which reacts faster in the Cannizzaro Reaction?
a) $\ce{OHC-Ph-NO2}$
b) $\ce{OHC-Ph-OCH3}$
A better hydride releasing group will be a better reactant, obviously. Therefore my answer was **b**, as $\ce{-OCH3}$ shows -I (inductive) as well as -R (resonance), as its in para position. This increases the $e^-$ conc... |
Which compound reacts faster in the Cannizzaro Reaction? |
> What is the amount of nitrate ions in $20.0\:\mathrm{g}$ of $\ce{Fe(NO_3)_3}$?
The chemical formula for the nitrate ion is $\ce{NO_3}$, I think.
The molar mass of $\ce{Fe(NO_3)_3}$ is $242~\mathrm{g~mol^{-1}}$ of which $186$ belong to $\ce{NO_3}$. That means that around $76.85\:\%$ of the substance is nitrate i... |
Allylic and benzylic compounds undergo oxidation with selenium dioxide to furnish either an allylic alcohol or an allylic carbonyl. But use of acetic acid as solvent stops the reaction at allylic alcohol stage due to formation of acetate esters.
One way to stop the further oxidation of allylic alcohols to give carbo... |
$\Delta G = \Delta H_\text{system}-T\Delta S_\text{system}$
When enthalpy is negative, the reaction is exothermic, which means it releases energy into the surroundings. If the system is losing energy, shouldn’t the entropy of the system always decrease? I understand mathematically t... |
I understand that elements use their valence electrons for their reactions and whatnot, and that the whole idea of the electron-dot structure is all about valence electrons. But why can't the other electrons play a part in it? |
Why does an element's chemical properties rely only on its valence electrons and not on anything else? |
Wherever you find potassium, there the isotopes are combined in a set percentage that exist everywhere the same in nature, but why is that? Does it have something to do with how the element is produced? |
Why is the relative natural abundance of isotopes of an element same everywhere? |
We know that Gibbs free energy is same as negative of 8.314 times temperature in kelvin times natural logarithm of equilibrium constant, or:
$$\Delta_\mathrm{r}G^\circ=-RT\ln K$$
Then, we also know Van't Hoff equation, like:
$$\ln\left(\frac{K_2}{K_1}\right)=\frac{-\Delta H^\circ}{R}\left(\frac{1}{T_2}-\frac{1}{T_1}... |
Let us say we have one glass of water and after that when we add one or two spoon of salt then we notice that salt dissolves in it but when we measure the water level we found that there is no difference between initial reading and final reading. So what's happening over there ? Why water level doesn't changed when sal... |
Why there is no change in water level when salt is added? |
I have a bag of titanium dioxide of pigment quality, unknown source. I am curious to know if the manufacturing process of titanium dioxide makes it likely that it contains any toxic by products / impurities.
Would it for example be safe to use pigment grade titanium dioxide to manufacture sunblock? |
Is pigment grade titanium dioxide likely to contain any impurities that are toxic? |
We know that the Gibbs free energy is related to the equilibrium constant by the following equation:
$$\Delta_\mathrm{r}G^\circ=-RT\ln K$$
We also know the Van't Hoff equation:
$$\ln\left(\frac{K_2}{K_1}\right)=\frac{-\Delta H^\circ}{R}\left(\frac{1}{T_2}-\frac{1}{T_1}\right)$$
$\left(R = 8.314\ \mathrm{J~mol^{-1... |
Why is data about limits of certain colors and visible spectrum in general so different in different sources? In Wikipedia, the numbers differ up to +/- 30 nm.
![English Wikipedia][1] ![German Wikipedia][2]
[1]: https://i.stack.imgur.com/rSlVg.png
[2]: https://i.stack.imgur.com/GQcDr.png |
I understand that we need to add $\ce{FeBr3}$ while brominating benzene in order to polarize the bromine molecule. However, we do not need to add such a Lewis Acid in the case of phenol, because it is activated by the $\ce{-OH}$ group, and so polarizes the bromine molecule on its own. Anisole is also highly activated, ... |
Why do we need to add FeBr3 for bromination of anisole, but not for bromination of phenol? |
Why is data about wavelengths of different colors and the visible spectrum in general so different in different sources? On Wikipedia, the numbers differ by up to $\pm\mathrm{30~nm}$.
![English Wikipedia][1] ![German Wikipedia][2]
[1]: https://i.stack.imgur.com/rSlVg.png
[2]: https://i.stack.imgur.com/GQ... |
Is a racemic mixture always an equi-molar solution of two enantiomers, both in the same state? Is it necessary for both isomers to be in the liquid state for racemisation to occur, or does racemisation also occur in the gaseous and solid states?
Thirdly,can the two enantiomers still form a racemic mixture if they are ... |
> Does this mean that the higher the concentration of bicarbonates, the better the quality for drinking?
Not necessarily. This is more a subjective question involving what tastes good to you.
> Should we choose the bottle of water with the highest concentration of these anions?
Assuming the water is actually m... |
Alcohol and water are miscible. I am coming across some chemicals that are soluble in alcohol and insoluble in water. Is solubility in a mixture of the two solvents always straightforward, or are there confounding variables?
E.g., if some chemical will dissolve to 100g/L alcohol at 25°C, then will its solubili... |
I'm a bit confused.
I've got this ["toy"](http://www.amazon.com/OWI-Salt-Water-Monster-Truck/dp/B007V5TEMW/ref=sr_1_fkmr1_1?ie=UTF8&qid=1434318147&sr=8-1-fkmr1&keywords=inpro+solar+car+salt+water) ...
with the help of this site I was abled to find out that the reaction stops with a lack of air. Link to the old [quest... |
Magnesium air-fuel cell or battery? |
Today I was told:
*When 2-chlorobutane is reacted with 2-chloropropane in the presence of sodium and dry ether the following products are formed: 2,3-dimethylpentane; 3,4-dimethylhexane; 2,3-dimethylbutane. 2,3-dimethylhexane, being most symmetric, is the major product.*
I'm not satisfied with the reason provided. Ca... |
According to the MSDS for titanium dioxide, the substance itself is suspected of causing cancer. See, for example, [this link](http://www.sigmaaldrich.com/MSDS/MSDS/DisplayMSDSPage.do?country=US&language=en&productNumber=14021&brand=SIAL&PageToGoToURL=http%3A%2F%2Fwww.sigmaaldrich.com%2Fcatalog%2Fproduct%2Fsial%2F14021... |
I would like to understand how a mixture of solvents works together.
For example, there are two solvents combined, and each one alone can dissolve some material, but one acts faster.
How do they interact when used in combination on the same material?
<br>
An example would be paint thinner, for example a m... |
I'm a bit confused.
I've got this ["toy"](http://www.amazon.com/OWI-Salt-Water-Monster-Truck/dp/B007V5TEMW/ref=sr_1_fkmr1_1?ie=UTF8&qid=1434318147&sr=8-1-fkmr1&keywords=inpro+solar+car+salt+water) ...
with the help of this site I was abled to find out that the reaction stops with a lack of air. Link to the old [quest... |
I'm a bit confused.
I've got this ["toy"](http://www.amazon.com/OWI-Salt-Water-Monster-Truck/dp/B007V5TEMW/ref=sr_1_fkmr1_1?ie=UTF8&qid=1434318147&sr=8-1-fkmr1&keywords=inpro+solar+car+salt+water) ...
with the help of this site I was abled to find out that the reaction stops with a lack of air. Link to the old [quest... |
I would like to understand how the polyester resin or epoxy catalyst works and to what degree it must be mixed with the base material in order to be effective.
Typical product instructions advise to thoroughly mix the catalyst for a specified period of time.
How thorough does this really have to be in order to ... |
How does the catalyst in a polyester resin or epoxy work? |
Is the relative natural abundance of isotopes of an element same everywhere? |
> The acceptable concentration of $\ce{CO}$ in the air is $10mg/m^3$. In
> a room that is $19m\cdot4.0m\cdot25m$, what is the acceptable mass in
> kilograms of $\ce{CO}$?
The room has a volume of $1900m^3$. Since there are $10mg$ of $\ce{CO}$ per $m^3$, there are $19000mg$ of $\ce{CO}$ in this room. That's $19kg$.... |
> The acceptable concentration of $\ce{CO}$ in the air is $10mg/m^3$. In
> a room that is $19m\cdot4.0m\cdot25m$, what is the acceptable mass in
> kilograms of $\ce{CO}$?
The room has a volume of $1900m^3$. Since there are $10mg$ of $\ce{CO}$ per $m^3$, there are $19000mg$ of $\ce{CO}$ in this room. That's $19kg$.... |
Today I was told:
> When 2-chlorobutane is reacted with 2-chloropropane in the presence of sodium and dry ether the following products are formed: 2,3-dimethylpentane; 3,4-dimethylhexane; 2,3-dimethylbutane. 2,3-dimethylhexane, being most symmetric, is the major product.
I'm not satisfied with the reason provided... |
Wherever you find potassium, the isotopes are presnt in a set percentage that exists the same everywhere in nature, but why is that? Does it have something to do with how the element is produced? |
> The acceptable concentration of $\ce{CO}$ in the air is $10\:\mathrm{mg/m}^3$. In
> a room that is $19\:\mathrm{m\cdot4.0\:m\cdot25\:m}$, what is the acceptable mass in
> kilograms of $\ce{CO}$?
The room has a volume of $1900\:\mathrm{m}^3$. Since there are $10\:\mathrm{mg}$ of $\ce{CO}$ per $\mathrm{m}^3$, ther... |
Is the relative natural abundance of isotopes of an element the same everywhere? |
As per one of the discussion in this web portal NH3 + H20 ---> NH4 + OH,
but in absorption refrigeration, the mixture is placed in the same container and then when it is heated the mixture is separated and NH3 changes the phase and becomes gas which moves further to cooling and water is trapped down to the reservoir... |
How does Ammonia and water mixture works in an absorption refrigeration? |
There exist a free online orbital calculator
http://www.chem.ucalgary.ca/SHMO/
When I draw cyclopropane it plots three molecular orbitals, unfortunately it doesn't use the Walsh orbitals.
Is there free online tool which can solve such a problem?
(Very nice would also be an android app. Please let me know if... |
Alcohol and water are miscible. I am coming across some chemicals that are soluble in alcohol and insoluble in water. If I know solubility in two solvents separately, is solubility in a mixture of the two always straightforward, or are there confounding variables?
E.g., if some chemical will dissolve to 100g/L alc... |
As per one of the discussion in this web portal $\ce{NH3 + H2O -> NH4 + OH}$,
but in absorption refrigeration, the mixture is placed in the same container and then when it is heated the mixture is separated and $\ce{NH3}$ changes the phase and becomes gas which moves further to cooling and water is trapped down to t... |
That's a good, concise statement of Bent's rule. Of course we could have just as correctly said that p character tends to concentrate in orbitals directed at electronegative elements. We'll use this latter phrasing when we examine methyl fluoride below. But first, let's expand on the definition a bit so that it is cle... |
Suppose I have a solid compound from which I want to extract a target chemical I know is soluble in acetone. So I crush and mix the compound in acetone, dissolving the target and suspending the detritus.
1. What are methods for filtering the detritus from the solution? I have frequently seen coffee filters used for... |
>What are methods for filtering the detritus from the solution? I have frequently seen coffee filters used for this purpose. Are commercial coffee filters considered "lab-grade?" Or, suppose that the target chemical has some affinity for cellulose, what alternatives exist for suspension filtration?
The method that c... |
[Lithium bromide refrigerator][1]
[1]: https://en.wikipedia.org/wiki/Absorption_refrigerator#Simple_salt_and_water_system
Why is lithium bromide used in absorption refrigerators? It is more expensive than sodium chloride. The wikipedia article on lithium bromide says it is extremely hygroscopic. However, i... |
Why is lithium bromide used in absorption refrigerators? |
Allylic and benzylic compounds undergo oxidation with selenium dioxide to furnish either an allylic alcohol or an allylic carbonyl. But use of acetic acid as solvent stops the reaction at allylic alcohol stage due to formation of acetate esters.
One way to stop the further oxidation of allylic alcohols to give carbo... |
"Most common" means the forms most frequently encountered in the entire scope of chemistry, which I'm pretty sure corresponds loosely to the most thermodynamically stable oxidation state. It is not always the case that the '-ate' ion is the most stable, however—as an example, see the links for chlorine below).
A det... |
Does all aldol reaction undergo cannizaro reaction?After all nucleophile can attack the carbonyl group always.
|
I searched on internet about rocket fuel and the most common fuel is $\ce{KNO3}$ + sugar (rocket candy), but I think that I could use another fuel methods, like using can with gas or using $\ce{HCl + Al}$.
My question is: Which one ($\ce{KNO3}$ + sugar, can with gas or $\ce{HCl + Al}$) gets more performance? Can I i... |
[Octasulfur][1] is just one of few different [allotropic forms][2] of sulfur. It happens to be the most stable form at room temperature, but different conditions favor different forms. Thus, for instance, sulfur vapor usually contains $\ce{S, S2, S4, S6, S8}$, and the higher the temperature, the lower is the amount of ... |
[Octasulfur][1] is just one of few different [allotropic forms][2] of sulfur. It happens to be the most stable form at room temperature, but different conditions favor different forms. Thus, for instance, sulfur vapor usually contains $\ce{S, S2, S4, S6, S8}$, and the higher the temperature, the lower is the amount of ... |
Why does oxygen form a double bond in $\ce{O2}$ but sulfur, also from group 16, forms single bonds in $\ce{S8}$?
|
Does all the species that experience aldol reactions also undergo cannizaro reacion? After all the nucleophile can always attack the carbonyl group.
|
As per one of the questions in this site $$\ce{NH3 + H2O -> NH4 + OH}$$
However, per another perspective in absorption refrigeration
> The mixture is placed in the same container. Then when it is heated the mixture is separated and $\ce{NH3}$ changes phase, becomes a gas which moves further to cooling, while water ... |
There exists [a free online orbital calculator](http://www.chem.ucalgary.ca/SHMO/).
When I draw cyclopropane it plots three molecular orbitals, but unfortunately it doesn't use the Walsh orbitals.
Are there any free online tools which can solve such the problem?
(It would be very nice if it would also be an an... |
The largest contribution to the entropy change will be the translational component, which is easy to evaluate using the [Sackur-Tetrode equation][1]
$$S^\circ_{\rm{trans}}=R\ln(bM^{3/2}T^{3/2})$$
where $b$ is a collection of constants with a value of 3.75 (mol/gK)$^{3/2}$ $M$ is the mass in g/mol, $T$ is temperature ... |
Can all species that undergo aldol reactions also undergo Cannizaro reactions? After all, the nucleophile can always attack the carbonyl group.
|
Can all species that undergo aldol reactions also undergo Cannizzaro reactions? After all, the nucleophile can always attack the carbonyl group.
|
The largest contribution to the entropy change will be the translational component, which is easy to evaluate using the [Sackur-Tetrode equation][1]
$$S^\circ_{\rm{trans}}=R\ln(bM^{3/2}T^{3/2})$$
where $b$ is a collection of constants with a value of 3.75 (mol/gK)$^{3/2}$ $M$ is the mass in g/mol, $T$ is temperature ... |
There exists [a free online orbital calculator](http://www.chem.ucalgary.ca/SHMO/).
When I draw cyclopropane it plots three molecular orbitals, but unfortunately it doesn't use the Walsh orbitals.
Are there any free online tools which can solve such the problem?
(It would be very nice if it would also be an an... |
Can the structure of an azide ion ($\ce{N3-}$) be $\ce{N#N\bond{->}N^-}$?
I know the actual structure but was asking whether the single bond can be shifted to a N to make it a triple bond and a coordinate bond with other Nitrogen. |
can the structure of azide contain a coordinated bond? |
Can the structure of an azide ion contain a coordinate bond? |
If we have an isolated pentane molecule at room temperature (RT) the Boltzmann energy $(E=k_BT)$ is approxately 0.59 kcal/mol = 207 $\ce{cm^{−1}}$. There is not enough energy for an electronic or vibrational excitation, so the molecule is in its electronic and vibratory ground state. However usually 10-20 rotational st... |
How to distribute the Boltzmann energy to internal and external motion? |
How do I extract cyanide from apple seeds? |
Both [amylose](https://commons.wikimedia.org/wiki/File:Amylose2.svg) and [cellulose](https://commons.wikimedia.org/wiki/File:Cellulose_Sessel.svg) have the same "monomer" structure (glucose), so what makes them look/form so differently?
![Amylose][2]![Cellulose][1]
[1]: https://i.stack.imgur.com/AohnP.png
... |
Why starch (amylose) and cotton (cellulose) are so different? |
The rise in pH can change the protein conformation by changing the ionic interactions and hydrogen bounds between two polypeptide chains. This is a fact that I understand very good because the amino-acid's ionization change with the pH. I would like to know if changing the pH value the hydrophobic interactions between... |
Can the structure of an azide ion ($\ce{N3-}$) be $\ce{N#N\bond{->}N^-}$?
I know the actual structure but was asking whether the single bond can be shifted to a N to make it a triple bond and a coordinate bond with other Nitrogen.
No this can't be a duplicate of "Hybridization of azide ion" because I am asking whet... |
The rise in pH can change the protein conformation by changing the ionic interactions and hydrogen bonds between two polypeptide chains. This is a fact that I understand very well because the change in amino-acid ionization with pH. I would like to know if by changing the pH value the hydrophobic interactions between t... |
So I was "happily" doing organic chemistry homework when I came across this question:
>(Give me a minute, uploading image)
I decided to take a look through my textbook to see what I was missing. The rules to compare resonance structure energies (and therefore determine relative stabilities) were in my textbook. It s... |
So I was "happily" doing organic chemistry homework when I came across this question:
![enter image description here][1]
I decided to take a look through my textbook to see what I was missing. The rules to compare resonance structure energies (and therefore determine relative stabilities) were in my textbook. It sai... |
Your summary is correct; [$\ce{NaCl}$ is more *soluble* than $\ce{LiCl}$ or $\ce{CaCl2}$][1], for that matter, but both $\ce{LiCl}$ or $\ce{CaCl2}$ are far more [*hygroscopic*][2]. The [explanation of hygroscopicity][3] involves various mechanisms, including adsorption (surface forces) and absorption (requiring transp... |
Consider two $\ce{H}$ atoms. Since the proton in one attracts the electron in another, they attract each other, and form a covalent bond ($\ce{H-H}$). Bond forming requires energy (436 kJ/mol for an $\ce{H-H}$ bond) – where does that energy come from?
If I put two $\ce{H}$ atoms in a container, would they form an $\... |
The melting and boiling points of noble gases are very low in comparison to those of other substances of comparable atomic and molecular masses. This indicates that only weak van der Waals forces or weak London dispersion forces are present between the atoms of the noble gases in the liquid or the solid state.
T... |
In the standard Periodic Table layout , all the elements upto 56 are in order i.e are in the same layout table. However, lanthanides and actinides are always shown separately from the layout like in [this][1] layout.
> What is the reason behind this structure?
> Is this standard layout or can I represent like th... |
Why lanthanides and actinides are shown separate from standard Periodic Table layout? |
And are the properties of amorphous solids vs. crystals explained by their structures? |
Do Crystals have stronger intermolecular bonds than amorphous solids? |
Do Crystals have stronger intermolecular bonds than amorphous solids and are the properties of amorphous solids vs. crystals explained by their structures? |
Today I was told:
> When 2-chlorobutane is reacted with 2-chloropropane in the presence of sodium and dry ether the following products are formed: 2,3-dimethylpentane; 3,4-dimethylhexane; 2,3-dimethylbutane. 3,4-dimethylhexane, being most symmetric, is the major product.
I'm not satisfied with the reason provided... |
Today I was told:
> When 2-chlorobutane is reacted with 2-chloropropane in the presence of sodium and dry ether the following products are formed:
- 2,3-dimethylpentane
- 3,4-dimethylhexane
- 2,3-dimethylbutane
> 3,4-dimethylhexane, being most symmetric, is the major product.
I'm not satisfied with the re... |
What is the reason for anomalous expansion of water? Why doesn’t it simply expand on heating or contract on cooling? Why it shows anomalous behavior at 4 degrees Celsius? Why not on 4.6 or 10 (or whatever) degrees Celsius? |
**How Did Wittig Come to Discover Lithium-Halogen-Exchange?**
Georg Wittig, discoverer of the [Wittig reaction][1], was studying the effect of ring strain on the strength of two neighboring carbons; by adding enough strain he expected to coax C-C bonds into forming diradicals:
![diyl][2]
Unfortunately tetraphen... |
http://chemistry.stackexchange.com/questions/31531/friedel-crafts-reaction-of-phenol
The answer to the question at the above link states that : "Like aniline, phenol too reacts to a very less extent during Friedal-Crafts reaction.
The reason being that the oxygen atom of phenol has lone pair of electrons which coor... |
Why does phenol not undergo Friedel-Crafts alkylation and acylation reactions, whereas anisole does? |
**How Did Wittig Come to Discover Lithium-Halogen-Exchange?**
Georg Wittig, discoverer of the [Wittig reaction][1], was studying the effect of ring strain on the strength of two neighboring carbons; by adding enough strain he expected to coax C-C bonds into forming diradicals:
![diyl][2]
Unfortunately tetraphen... |
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