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I'm currently stuck on problem #30 for the Chemistry Olympiad 2015 local exam which reads:
>For a reversible exothermic reaction, what is the effect of increasing temperature on the equilibrium constant ($K_\mathrm{eq}$) and on the forward rate constant ($k_\mathrm{f}$)?
>
>(A) $K_\mathrm{eq}$ and $k_\mathrm{f}$ b... |
Why are the two bonds in sulphur dioxide identical? |
Triatomic molecules are either linear or bent. If we analyse the $\ce{SO2}$ molecule, it turns out that it is **bent**.
I know that $\pi$ bonds do not alter shape, but merely the bond lengths.
Now since one of the bonds between S and O is a p$\pi$-p$\pi$ bond and the other bond is a d$\pi$-p$\pi$ bond, the two ... |
What is the " ... Article like this ..." that you write at the very beginning of your post ?
Then, try to be clear in using the word "cathode". A cathode is the electrode where a reduction happens, whatever its working mode (cell or electrolysis). So when recharging a Li-ion battery, the $\ce{Li+}$ ion are going to... |
First time posting questions here, so let me know if I need to edit anything.
I need to decide $dC/dt$ and $dP/dt$ when the reaction is like this, where I don't have any info about $S, E$ or $P$:
$$2S + E \overset{k_a}{\longrightarrow} C \overset{k_c}{\longrightarrow} 2P + E, \quad C \overset{k_b}{\longrightarrow... |
How to find the reaction rate in an enzyme reaction? |
Articles like [this][1] claim oxygen can evolve from layered metal oxide cathode materials when charging the Li-ion battery.
Is it the high positive potential given to the cathode while charging pulling the electrons from the chemical bonds of the cathode materials and thus cause the decomposition to evolve oxygen?
I... |
I have been using carbon paper (Carbon sheet 99.8% from STERM CHEMICALS) to load catalysts for fuel cell study. Just now, I realized that for a 1 cm^2 piece the resistance is about 3 ohms!
Is that a typical value? I can't find any info on Google or the seller's webpage.
Thanks! |
What is the typical resistance of a piece of 1 cm^2 of carbon paper? |
**Question :**
>Why energy is released when an electron is added to a neutral atom?
I read somewhere
>“When electrons are added to an atom, the increased negative charge puts stress on the electrons already there, causing energy to be released.”
I didn't understand *What is stress and how energy is released d... |
I was recently looking at how long can Remdesivir be stored in its different forms.
I came up across several articles provided by the [FDA][1] and [Gilead Sciences][2] and [others][3].
What caught my eye was the fact that after you reconstitute Remdesivir with sterile water you cannot store it at all! The manual ... |
How accurate is the drug manual provided with an injectable drug? |
1)Today I came across a problem which asks to find the order of dehydration of 2-hydroxycyclohexanone(1), 3-hydroxycyclohexanone(2),4-hydroxycyclohexanone(3). The answer is 2>3>1 But I thought answer should be 2>1>3 cause in 2 and 3 the product would be conjugated and hence more stable.
2)My second confusion is regar... |
For "nitrogen family" and "boron family" the trend goes that in a period, the electron affinity in case of group 15 is less than that of group 14. This is attributed to the half-filled p-subshell which tends not to gain an electron. But this true till antimony only. Bismuth has a greater electron affinity as compared t... |
My teacher taught me that *compounds having intramolecular H-Bonding are relatively less soluble in water as they will not involve in H-Bonding with water appreciably while those able to do intermolecular H-Bonding will appreciably form H-Bonding with water, and thus the latter ones will be relatively more soluble in w... |
Why is Maleic Acid more soluble in water than its trans isomer Fumaric Acid? |
This does not answer your question exactly, but I hope this can shed some light on the anomalous behaviour of anilinium cations.
First of all, it is not true that the para-product is always favoured with the $\ce{NH3+}$ ion, it depends on the reaction conditions. There are two effects to consider here—1) kinetic/the... |
This does not answer your question exactly, but I hope this can shed some light on the anomalous behaviour of anilinium cations.
First of all, it is not true that the para-product is always favoured with the $\ce{NH3+}$ ion, it depends on the reaction conditions. There are two effects to consider here—1) kinetic/the... |
My teacher taught me that compounds having intramolecular H-Bonding are relatively less soluble in water as they will not involve in H-Bonding with water appreciably while those able to do intermolecular H-Bonding will appreciably form H-Bonding with water, and thus the latter ones will be relatively more soluble in wa... |
1)Today I came across a problem which asks to find the order of dehydration of 2-hydroxycyclohexanone(1), 3-hydroxycyclohexanone(2),4-hydroxycyclohexanone(3). The answer is 2>3>1 But I thought answer should be 2>1>3 cause in 2 and 3 the product would be conjugated and hence more stable.
2)My second confusion is regar... |
First time posting questions here, so let me know if I need to edit anything.
I need to decide $dC/dt$ and $dP/dt$ when the reaction is like this, where I don't have any info about $S, E$ or $P$:
$$2S + E \overset{k_a}{\longrightarrow} C \overset{k_c}{\longrightarrow} 2P + E, \quad C \overset{k_b}{\longrightarrow... |
In $[Co(edta)]^-$ and $[Co(en)_3]^{3+}$, $[Co(edta)]^-$ has 5 rings in total and in $[Co(en)_3]^{3+}$ there are 3 rings. And the stability of the first one is more than that of the second one, the reason I was told was that *a complex with more number of rings is more stable*. <br>
Why is this so? |
What other known reductants for SiO₂ could potentially be used for producing silicon from silica in an arc furnace?
[![enter image description here][1]][1]
Read more: http://www.madehow.com/Volume-6/Silicon.html#ixzz6uKynirns
[1]: https://i.stack.imgur.com/4cvOe.png |
Dead trees or charcoal is generally used as a reductant in the production of pure silicon for use in industry what other reductants could be used? |
$\ce{[Co(edta)]^-}$ has 5 rings in total and in $\ce{[Co(en)_3]^{3+}}$, there are 3 rings. The stability of the former is more than that of the latter. The reason I was told was that *a complex with more number of rings is more stable*.
Why is this so? |
The Given compound is treated with Excess H2 and Pt (See the Attached Image)
**(a) - The given compound.**
**(b) - What the answer should be (acc to me).**
**(c) - What the actual answer is.**
Q1 - How is the chirality center at the top right even a chirality center as the carbon has 2 identical groups attache... |
How can a compound having a plane of symmetry be Chiral? |
I have been researching chemical reactions of inorganic catalysts and enzymes and cannot find a chemical process where an inorganic compound can be replaced by an enzyme (or vice versa) and have the same products. I have looked at article after article with no luck.
What is an example of chemical reaction that invol... |
What is an example of chemical reaction that can be assisted by both an inorganic catalyst and an enzyme? |
I think you are getting confused between chirality and E-Z isomerism in cyclic structures. So let's clear that up first.
According to IUPAC:
>[**chirality**](http://goldbook.iupac.org/C01058.html)
The geometric property of a rigid object (or spatial arrangement of points or atoms) of being non-superposable on ... |
The compound( Given in the image below) is treated with $\ce{excess H2 in Pt}$.
Here, (a) - The given compound. (b) - What the answer should be according to me.
(c) - What the actual answer is:
[![enter image description here][1]][1]
>Q1 - How is the chirality center at the top right even a chiral center,... |
First time posting questions here, so let me know if I need to edit anything.
I need to decide $dC/dt$ and $dP/dt$ when the reaction is like this, where I don't have any info about $S, E$ or $P$:
$$2S + E \overset{k_a}{\longrightarrow} C \overset{k_c}{\longrightarrow} 2P + E, \quad C \overset{k_b}{\longrightarrow... |
Suppose I am reacting HCl with CuCO3.
Experiment 1: I use 2g powdered CuCO3
Experiment 2: I use 4g powdered CuCO3
All other variables are kept constant.
Will this have any affect on rate of reaction? Will the 4g react faster because of more particles available for collision? |
Does mass affect rate of reaction? |
This does not answer your question exactly, but I hope this can shed some light on the anomalous behaviour of anilinium cations.
First of all, it is not true that the para-product is always favoured with the $\ce{NH3+}$ ion, it depends on the reaction conditions. There are two effects to consider here—1) kinetic/the... |
I read two reactions which I would want to specify first: <br>
<li> $\ce{Na2O2 + O3 + H2O -> 2NaOH + 2O2}$</li>
<li> $\ce{2KOH + 5O3 -> 2KO3 + 5O2 + H2O}$ </li>
<br>
Now my question is that does $\ce{NaOH}$ also undergo a further reaction to produce $\ce{NaO3}$ or not? Since both are alkali metals and with relativ... |
Does $\ce{NaOH}$ react with $\ce{O3}$ to produced $\ce{NaO3}$? |
I was reading the following article on wikipedia about [Hydroponics][1]
"Unlike most nutrients, plants can tolerate a high concentration of the SO2−
4, selectively absorbing the nutrient as needed.[19][61][62] Undesirable counterion effects still apply however. "
Can somebody explain me what is meant by counteri... |
What are counterion effects? |
If the initial pressure of $\ce{CO}$ and $\ce{H_2O}$ are equal, then let $p_{\ce{H_2O}}=p_{\ce{CO}}=x$.
Since their total is 1.5 bar, i.e. $\ce{p_{H_2O} + p_{CO}}=1.5$
Can you solve this equation?
____
Edit: This is under the assumption that there was originally no carbon dioxide or hydrogen, I have not yet ma... |
This is in the context of the various changes in oxidation state the permangananate ion can undergo with the variation of the pH of the medium. Besides the cases of strongly basic and strongly acidic media, the case for neutral media (with reduction to $\ce{MnO2}$) in my notes has a footnote; that this medium is in fac... |
Why is the aqueous solution of KMnO4 slightly basic? |
Does NaOH react with O3 to produced NaO3? |
On a small scale, hydrogen gas is certainly an option. Here is a paper: [Reduction Kinetics of Metal Oxides by Hydrogen](https://www.researchgate.net/profile/Jie-Dang-3/publication/264487666_Reduction_Kinetics_of_Metal_Oxides_by_Hydrogen/links/5a5fff4a0f7e9b964a1edf52/Reduction-Kinetics-of-Metal-Oxides-by-Hydrogen.pdf)... |
On a small scale, hydrogen gas is certainly an option. Here is a paper: [Reduction Kinetics of Metal Oxides by Hydrogen](https://www.researchgate.net/profile/Jie-Dang-3/publication/264487666_Reduction_Kinetics_of_Metal_Oxides_by_Hydrogen/links/5a5fff4a0f7e9b964a1edf52/Reduction-Kinetics-of-Metal-Oxides-by-Hydrogen.pdf)... |
When my teacher was teaching me positive deviation from Raoult's Law, he told me that in this case
$P_{solution}>P_A^°χ_{A} + P_B^°χ_{B}$
He told that here the solute-solvent interactions are weaker than the solute-solute interactions and solvent-solvent interactions due to which more vapours can be formed from the... |
Why in positive deviation from Raoult's Law partial vapour pressure of a liquid component is greater than what is predicted by Raoult's Law? |
I was reading the following article on wikipedia about [Hydroponics][1]
> Unlike most nutrients, plants can tolerate a high concentration of the
> $\ce{SO4^2−}$, selectively absorbing the nutrient as needed.
> Undesirable counterion effects still apply however.
Can somebody explain me what is meant by counterio... |
As far as I could remember, in the same period, a bond to a more electronegative atom implies in a more polar and stronger bond, due to the greater ionic character. However the bond dissociation energy for the C-X series follows the order: C-F > C-O > C-C > C-N. The same for H-X: H-F > H-O > H-C > H-N.
Why are the b... |
Why is a C-N bond weaker than a C-C? |
How stable is Remdesivir when vial vacuum is broken and/or it is reconstituted with sterile water? |
I was taught that according to CIP rules, we must check the priority order for the substituents. But how can we do the same with molecules with cyclic groups as substituents?
Consider this molecule as an example
[![enter image description here][1]][1]
How do we compare the substituents?
How to decide E Z c... |
My teacher was teaching me the boiling point composition curve for fractional distillation and in the class notes he gave the following diagram (I have given below). It says that the residue starts accumulating at the point on the vaprous line just above the liquidus line (above $χ_{A},χ_{B}$). Note that $χ_{A},χ_{B}$ ... |
The following reaction is usually carried out to test for the carbonate anion in an inorganic salt;
$$\ce{CO3^2-+BaCl2/CaCl2 -> BaCO3/CaCO3(s)}$$
The resulting carbonate is stated to be an insoluble precipitate, and also to be dissolvable in mineral acids like $\ce{HCl}$.
How does that happen? If the initial tes... |
How does the reaction of Alkyl Halides with sodium nitrite in DMF proceed? |
First time posting questions here, so let me know if I need to edit anything.
I need to decide $dC/dt$ and $dP/dt$ when the reaction is like this, where I only know we must have 2 substrates $S$ to react with the enzyme $E$ at the same time:
$$2S + E \overset{k_a}{\longrightarrow} C \overset{k_c}{\longrightarrow}... |
I have confusion regarding the following problem [![enter image description here][1]][1]
My attempt at the solution:
I tried to find out the products and compare their stability:
[![enter image description here][2]][2]
[1]: https://i.stack.imgur.com/JZdgv.jpg
[2]: https://i.stack.imgur.com/pYjhS.jpg
N... |
I was taught that according to CIP rules, we must check the priority order for the substituents. But how can we do the same with molecules with cyclic groups as substituents?
Consider this molecule as an example:
[![Tetra-substituted ethene][1]][1]
How do we compare the substituents?
How to decide $(E/Z)$ ... |
I have confusion regarding the following problem which asks to arrange the given compounds in decreasing order of their degree of dehydration [![enter image description here][1]][1]
My attempt at the solution:
I tried to find out the products and compare their stability:
[![enter image description here][2]][2]
... |
I was aware of the reaction of alkyl halides with Aqueos Sodium Nitrite which results in the formation of an alkyl nitrite but I came across the following reaction and was confused of how that would work?
$\ce{R-X + NaNO2 ->[DMF] R-NO2}$
DMF being the solvent here, I'm pretty sure it's safe to assume it w... |
I was taught that according to CIP rules, we must check the priority order for the substituents. But how can we do the same with molecules with cyclic groups as substituents?
How do we compare the substituents for the following molecule?
[![Tetra-substituted ethene][1]][1]
How to determine *E*–*Z* configuratio... |
I have been researching chemical reactions of inorganic catalysts and enzymes and cannot find a chemical process where an inorganic compound can be replaced by an enzyme (or vice versa) and have the same products. I have looked at article after article with no luck.
What is an example of chemical reaction that invol... |
I am confused regarding the following problem which asks to arrange the given compounds in decreasing order of their degree of dehydration
[![enter image description here][1]][1]
My attempt at the solution:
I tried to find out the products and compare their stability:
[![enter image description here][2]][... |
While revising ***Thermodynamics and Thermochemistry*** from revision material published by _Arihant publications_ I encountered following mentioned statement.
[![enter image description here][1]][1]
>During dissolution, physical state of the compound changes while during hydration, there is no change in the phys... |
While revising ***Thermodynamics and Thermochemistry*** from revision material published by _Arihant publications_ I encountered the following mentioned statement.
[![enter image description here][1]][1]
>During dissolution, the physical state of the compound changes while during hydration, there is no change in ... |
In several sources I have read that heavier isotopologues eluate earlier than lighter ones.
As explanation vapor isotope effects are given.
But this is something I do not understand. I tought in a GC column substances are separated by their different vapor pressures and the longer a substance stays in the gas phase the... |
I am confused regarding the following problem which asks to arrange the given compounds in decreasing order of their degree of dehydration
[![enter image description here][1]][1]
My attempt at the solution:
I tried to find out the products and compare their stability:
[![enter image description here][2]][... |
I read two reactions which I want to specify first:
- $\ce{Na2O2 + O3 + H2O -> 2NaOH + 2O2}$
- $\ce{2KOH + 5O3 -> 2KO3 + 5O2 + H2O}$
Now my question is that does $\ce{NaOH}$ also undergo a further reaction to produce $\ce{NaO3}$ or not? Since both are alkali metals and with relatively similar sizes (?) I though... |
I read two reactions which I want to specify first:
- $\ce{Na2O2 + O3 + H2O -> 2NaOH + 2O2}$
- $\ce{2KOH + 5O3 -> 2KO3 + 5O2 + H2O}$
Does $\ce{NaOH}$ also undergo a further reaction to produce $\ce{NaO3}$ or not? Since both are alkali metals and with relatively similar sizes (?) I thought it could but Google do... |
It's implied that the right structure is the more stable carbocation because it undergoes the second half of an SN1 reaction.
[![enter image description here][1]][1]
I'm also not sure why the MeOH attacks the carbon next to the carbocation and not the oxygen itself, where it has the positive charge (doesn't the nucle... |
What is the most stable enolic form of 1-Phenylbutan-1,3dione? |
It's implied that the right structure is the more stable carbocation because it undergoes the second half of an S<sub>N</sub>1 reaction.
[![enter image description here][1]][1]
I'm also not sure why the $\ce{MeOH}$ attacks the carbon next to the carbocation and not the oxygen itself, where it has the positive cha... |
It's implied that the right structure is the more stable carbocation because it undergoes the second half of an S<sub>N</sub>1 reaction.
[![enter image description here][1]][1]
I'm also not sure why the $\ce{MeOH}$ attacks the carbon next to the carbocation and not the oxygen itself, where it has the positive cha... |
It's implied that the right structure is the more stable carbocation because it undergoes the second half of an S<sub>N</sub>1 reaction, but I'm not entirely sure why:
[![enter image description here][1]][1]
I'm also not sure why the $\ce{MeOH}$ attacks the carbon next to the carbocation and not the oxygen itself... |
### Question
> [![enter image description here][1]][1]
>
> Which form of 1-phenylbutan-1,3-dione is more stable?
### Answer
> 3-Hydroxy-1-phenylbut-2-enone
### My question
I've been told that between the above two, 3-hydroxy-1-phenylbut-2-enone is more stable because the double bond is in the middle ... |
Determining the most stable enolic form of 1-phenylbutan-1,3-dione? |
What's the difference between the following compounds? |
What's the difference between the co-ordination compounds $\ce{[Co(H2O)6]}$ and$\ce{[Co(H2O)6]^2+}$?
|
What's the difference between the co-ordination compounds $\ce{Co.(H2O)6}$ and$\ce{[Co(H2O)6]^2+}$?
|
I am an organic chemistry student learning how atomic orbitals interfere to give rise to molecular obitals. The image below suggests that each of the hydrogens' atomic orbitals interfere both constructively AND destructively. How is this possible? More fundamentally, how does the 1s atomic orbital of a hydrogen atom ha... |
How do atomic orbitals interfere both constructively AND destructively to give two molecular orbitals? |
For "nitrogen family" and "carbon family" the trend goes that in a period, the electron affinity in case of group 15 is less than that of group 14. This is attributed to the half-filled p-subshell which tends not to gain an electron. But this true till antimony only. Bismuth has a greater electron affinity as compared ... |
Unfortunately, in quantum mechanics there is rarely an explanation "in simple terms." Quantum mechanics is a mathematical construct that so far seems to predict the results of all experiments that have been done to test it, but explaining those maths in terms of anything we have learned from the larger-than-quantum sca... |
I was taught that according to CIP rules, we must check the priority order for the substituents. But how can we do the same for molecules with cyclic groups as substituents?
How do we compare the substituents for the following molecule?
[![Tetra-substituted ethene][1]][1]
How to determine *E*–*Z* configuration... |
I read two reactions which I want to specify first:
- $\ce{Na2O2 + O3 + H2O -> 2NaOH + 2O2}$
- $\ce{2KOH + 5O3 -> 2KO3 + 5O2 + H2O}$
Does $\ce{NaOH}$ also undergo a further reaction to produce $\ce{NaO3}$ or not? Since both are alkali metals and with relatively similar sizes(?), I thought it could, but Google d... |
Does NaOH react with O3 to produce NaO3? |
The reaction: Zn(s) + 2 AgNO3 (aq) → 2 Ag(s) + Zn(NO3)2 (aq)
takes place in a calorimeter.
30 cm3 of a 1.20 mol dm−3 solution of silver nitrate with an excess of zinc is used. If the value of ∆rH is −365.1 kJ mol−1 and all solutions are assumed to have a density of 1.00 g cm−3 and a specific heat capacity of 4.18 J ... |
I was solving a bunch of reactions when I encountered the following:
[![enter image description here][1]][1]
So for the first question:
[![enter image description here][2]][2]
This is a Reimer-Tiemann reaction. I felt that the tautomerisation would result in the deuterium getting attached to the phenolic $\ce{O^-}$... |
It is important to note that the two structures shown aren't actually different. That's what resonance implies that in reality, it exists in between both of the as a 'hybrid'.
So it is not right to state that the nucleophile attacks on the left structure 'or' the right.
---
Coming to the carbon, (agai... |
I was solving a bunch of reactions when I encountered the following:
[![enter image description here][1]][1]
So for the first question:
[![enter image description here][2]][2]
This is a Reimer-Tiemann reaction. I felt that the tautomerisation would result in the deuterium getting attached to the phenolic $\ce{O... |
While revising ***Thermodynamics and Thermochemistry*** from revision material published by _Arihant publications_ I encountered the following mentioned statement.
> During dissolution, the physical state of the compound changes while during hydration, there is no change in the physical state of the compound.
- H... |
Activated carbon and Silica gel both have a high surface area.
If I understand correctly it is possible to trap stuff inside activated charcoal pores to give it specific retention properties (by exposing it to functionalizing conpounds while heated to open up the pores?).
Is it possible to likewisz trap stuff ... |
Is it possible to functionalize silica gel as Activated Carbon can be? How? |
If I understand correctly it is possible to trap stuff inside activated charcoal pores to give it specific retention properties (by exposing it to functionalizing compounds while heated to open up the pores?).
When a solution for instance is passed through activated AC, what happens inside the pores with the funct... |
How does functionalized activated charcoal work? |
Activated carbon and Silica gel both have a high surface area.
If I understand correctly it is possible to trap stuff inside activated charcoal pores to give it specific retention properties (by exposing it to functionalizing conpounds while heated to open up the pores?).
Is it possible to likewise trap stuff ... |
The following reaction is usually carried out to test for the carbonate anion in an inorganic salt;
$$\ce{CO3^2- +BaCl2/CaCl2 -> BaCO3/CaCO3(s) + 2 Cl-}$$
The resulting carbonate is stated to be an insoluble precipitate, and also to be dissolvable in mineral acids like $\ce{HCl}$.
How does that happen? If the in... |
Please let me start with an apology - I am not a chemist. I'm helping my son with Matlab as he is having trouble learning differential equations as they apply to chemical kinetics. His task is to solve for the equilibrium concentrations for a reaction A+B=C.
We are given the forward and backward rates and the in... |
What is the difference between the terms photochemical and photophysical properties? What are some examples from each category? |
I'm helping my son with Matlab as he is having trouble learning differential equations as they apply to chemical kinetics. His task is to solve for the equilibrium concentrations for a reaction $$\ce{A + B = C}.$$
We are given the forward and backward rates and the initial concentrations of the reactants and produ... |
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