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At which point does CO2/H20 form in internal combustion engines? |
I'm attempting to answer a question from my textbook, however the answer that the textbook provides doesn't make sense to me.
The [question][1]:
> Laura, a VCE chemistry student, loves graphs and wanted to represent an equilibrium reaction by using graphs. The reaction she chose was:
>
> $\ce{Fe^{3+}(aq) + SC... |
I was reading about semiconductors and found out that semiconductors are doped with either 13th group or 15th group elements which are named P type and N type semiconductors respectively. In N type semiconductors I found out about the following:
[![N-type semiconductor][1]][1]
Now my question is, why does... |
I was reading about semiconductors and found out that semiconductors are doped with either 13th group or 15th group elements which are named p-type and n-type semiconductors, respectively. In n-type semiconductors I found out about the following:
[![N-type semiconductor][1]][1]
Why does antimony form four bonds w... |
While [this question][4] comes close, it doesn't quite answer my question.
Adding heat to oxygen & a hydrocarbon breaks the atoms apart and they reform into carbon dioxide and water. I get that.
I want to know **specifically at what point** the water and carbon dioxide are formed?
As I understand it the heat ... |
At which point does carbon dioxide and water form in internal combustion engines? |
From Wikipedia: Global Warming Potential:
GWP values and lifetimes:
Nitrous oxide lasts about 121 years in the atmosphere, causes about 280 times as much warming over 20 years, but about 300 times as much over 100 years.
HFC-23 lasts about 222 years, causes about 11,400 times the warming over twenty years, b... |
How can certain short-lived chemicals cause more global warming in the long term, relative to carbon dioxide, than they do in the short term? |
I'm attempting to answer a question from my textbook, however the answer that the textbook provides doesn't make sense to me.
The [question][1]:
> Laura, a VCE chemistry student, loves graphs and wanted to represent an equilibrium reaction by using graphs. The reaction she chose was:
>
> $\ce{Fe^{3+}(aq) + SC... |
In my book (NCERT India) list of values of electron gain enthalpies of various elements are given. According to that list, oxygen has less negative electron gain enthalpy than Selenium, Tellurium and Polonium. Shouldn't it be the opposite because electron gain enthalpy becomes less negative down a group?[![enter image ... |
Why do Selenium , Tellurium and Polonium have more negative electron gain enthalpy than oxygen? |
**Combustion reactions are complicated even when they result in simple products**
Part of the problem with answering the question "at what point are water and carbon dioxide formed" is that the reactions occuring in combustion are very complicated and not at all well represented by the simple versions shown in the q... |
We have hydroxide anion, methoxide anion, bisulfide anion , triphenyl phosphine, azide anion , 1-pyrrolidine cyclohexene.
We want to tell which of the above species are better nucleophiles than acetate anion.
We know that good nucleophile is a weak base, (I know there might be exceptions like cyanide anion), ... |
> Why do these ambimodal transition states occur?
I don't know that there is a general reason for that. Potential energy surfaces are complicated. Very often, there is an abundance of local minima, separated by potential energy barriers. It is similar to what happens with mountain chains and valleys, but with many ... |
I have the following observations:
* When I put a solution of glucose (80 g/ℓ) and ammonium chloride (20 g/ℓ) in a drying cabinet at 37°C (maybe a bit warmer) a brown substance forms when all (or most) of the water has evaporated.
* When I add water to the reaction product, the substance dissolves within minutes... |
What reaction happens between glucose and ammoniom chloride when drying? |
> Is there any existing examples of single-molecule magnets with permeability that can be controlled via altering current flow just like in case of electromagnets? If not, is there an explanation why it is not possible?
Short answers: **no**, and **not yet**.
Longer answer, and a warning that I'm using recent res... |
> Is there any existing examples of single-molecule magnets with permeability that can be controlled via altering current flow just like in case of electromagnets? If not, is there an explanation why it is not possible?
Short answers: **no**, and **not yet**.
Longer answer, and a warning that I'm using recent res... |
In one lecture at a recent MCR-X conference I was puzzled by a side-note "f-hole is critical to describe DoS of $\ce{IrO2}$ correctly." The context was DFT periodic plane-wave calculations with pseudization of the core electrons.
This implies that f-electrons are somewhat involved into chemistry of Ir. More precise... |
> Is there any existing examples of single-molecule magnets with permeability that can be controlled via altering current flow just like in case of electromagnets? If not, is there an explanation why it is not possible?
Short answers: **no**, and **not yet**.
Longer answer, and a warning that I'm using recent res... |
In general soft nucleophiles do 1,4 conjugate addition to a carbonyl carbon under thermodynamic control. Will soft nucleophiles like organo-cuprates undergo 1,4 addition if the β site is more sterically hindered than the carbonyl carbon. Will 1,4-addition still form the more favorable product?
For example, if I cons... |
>Is compound I formed by $\mathrm{S_N}$2 and compound II formed via $\mathrm{S_N}$1 after a carbocation rearrangement? Or is there some rearrangement I'm not aware of?
For the first question, the answer is probably not because the mechanism of a given reaction is mainly based on the condition used in the reaction (a... |
Acid titration of sodium acetate in the presence of sodium ethoxide, is it possible? |
>Is compound I formed by $\mathrm{S_N}$2 and compound II formed via $\mathrm{S_N}$1 after a carbocation rearrangement? Or is there some rearrangement I'm not aware of?
For the first question, the answer is probably not because the mechanism of a given reaction is mainly based on the condition used in the reaction (a... |
Helium is the most unreactive element but can it form chemical compounds under special conditions besides the helium hydride ion,or have any other helium compounds have been found in space? |
Can helium ever have any chemical compounds besides HeH+? |
Can helium ever have any chemical compounds or ions besides HeH+? |
Organotin compounds(organostannane chemistry) are compounds with the carbon-tin bond,but tin itself isn't toxic nor carbon or hydrogen. But some of them are as toxic as cyanide and why is this?
https://en.wikipedia.org/wiki/Organotin_chemistry |
Why are organotin compounds so toxic? (Please forgive my mistakes) |
The *cyaphide* anion $\ce({CP)-}$ should be chemically similar to its nitrogen analogue cyanide. $\ce{(CN-})$ But unlike it's counterpart it readily polymerizes so it has only been found in outer space naturally. However, it should form compounds that should be the same like cyanides.For example sodium cyanide (NaCN)... |
It should make sense that phosphorus has the positive charge,and gold itself has the negative charge in gold phosphide because phosphorus has a lower electronegativity than gold (phosphorus is 2.19, gold is 2.54),but then again they can both just share electrons. Is this true or not? |
Is Chromium (VI) fluoride be synthesized properly? |
So this compound is supposed to have all of the stable halogens a part of this molecule ,fluorine,chlorine ,bromine and iodine. Is it really able to be synthesized and actually not decompose the moment it goes outside of the lab?
Link :http://wiki/Bromochlorofluoroiodomethanehttps://en.wikipedia.org/ |
What is the role of dichloromethane in the Ozonolysis / Criegee reaction? |
Why is $\ce{CH2Cl2}$ used in ozonolysis of alkenes and alkynes? What role does it play in the reaction? Is dichloromethane a common solvent for organic reactions and used for its inertness, or is it particularly used in ozonolysis reactions? If it is the latter case, how does it enhance the ozonolysis reaction? |
What is the role of dichloromethane in the ozonolysis / Criegee oxidation? |
After having decided that the keto-group is the highest priority, this is a ketone. However, does the double bond become C2, or does the amino become C3?
In locant placement, do we prioritize **double bonds over substituents**, or other **substituents over double bonds**? (Or is it just a matter of having the small... |
In my book(NCERT India) a list of values of electron gain enthalpies of various elements is given. According to that list, oxygen has less negative electron gain enthalpy than selenium, tellurium and polonium. Shouldn't it be the opposite because electron gain enthalpy becomes less negative down a group?
[![Electron... |
Why do selenium , tellurium and polonium have more negative electron gain enthalpy than oxygen? |
I'm supposed to balance the following equation:
$$\text{Potassium chlorate (heated)} \rightarrow \text{Potassium chloride + Oxygen}$$
But I don't understand what is meant by the label "heated" in front of the first element. Do I ignore it, or am I supposed to add another element to the reactants of the equation? |
During the lecture in my chemistry class, my teacher posed the following problem:
> Arrange in terms of increasing vapor pressure:
>
> a) $\pu{0.5m}$ sugar
>
> b) $\pu{0.5m} ~ \ce{NaCl}$
>
> c) $\pu{2m}$ ethylene glycol
>
> d) $ \pu{2m} ~\ce{ LiBr}$
The answer turned out to be: d, c, b, a. However, I do n... |
>A reaction has $\Delta H_\textrm{rxn} = \pu{-107 kJ}$ and $\Delta S_\textrm{rxn} = \pu{285 J/K}$. At what temperature is the change in entropy for the reaction equal to the change in entropy for the surroundings?
My thoughts:
I wasn't really sure if there was an equation that related the entropy and the enthalpy... |
When using a boiling tube to boil a liquid, I am frequently advised to move the boiling tube in and out of the Bunsen flame and when the liquid starts to boil, remove the tube from the flame for a few seconds before resuming. Why is this so?
|
> The heat of neutralization of $\ce{HCl(aq)}$ by $\ce{NaOH}$ is $\pu{-55.9 kJ/mol}$ $\ce{H2O}$ produced. If $\pu{50ml}$ of $\pu{1.6M}$ $\ce{NaOH}$ at $\pu{25.15^\circ C}$ is added to $\pu{25ml}$ of $\pu{1.79M}$ $\ce{HCl}$ at $\pu{26.34^\circ C}$ in a plastic foam cup calorimeter, what will be solution temperature be i... |
I am an immunology master student without prior knowledge of biochemistry.
Could someone explain me the following 6 reactions?
What I want to understand is why exactly the reactions happen at **this** site ( in terms of donor/acceptor ). What is the donor, what is the acceptor?
![protein modifications1][1... |
Your approach seems correct. What is the "correct" numerical value of the answer according to your source?
I plugged in your equation to [Wolfram Alpha](http://www.wolframalpha.com/input/?i=Solve%5Bx+%281%E2%88%92y%29%5E2%3D4y%5E3%2C+y%5D), but using $x$ instead of an explicit $10^8$ as the factor on the left-hand ... |
I am an immunology master student without prior knowledge of biochemistry.
Could someone explain to me the following 6 reactions?
What I want to understand is why exactly the reactions happen at **this** site ( in terms of donor/acceptor ). What is the donor, what is the acceptor?
>### GWP values and lifetimes:
>
>Nitrous oxide lasts about 121 years in the atmosphere, causes about 280 times as much warming over 20 years, but about 300 times as much over 100 years.
>
>HFC-23 lasts about 222... |
In benzene and 1,3 - Cyclohexadiene, which one has greater C=C bond length? |
I want to make a sample for proton NMR signal-to-noise-ratio measurement. It is conventional to use 1% ethylbenzene in d-chloroform, as specified here:
https://www.drugfuture.com/Pharmacopoeia/usp38/data/v38332/usp38nf33s2_c761.html
I have two questions:
1) What is meant, exactly, by 1% ethylbenzene? In some pl... |
In benzene and 1,3-cyclohexadiene, which one has greater C=C bond length? |
Suppose we have an ideal gas filled inside a container fitted with piston.External pressure is equal to internal pressure.
Now if we suddenly decrease the external pressure, we say that the gas will expand till the intensity and external pressure become equal.
But shouldn't the gas expand beyond that point becaus... |
When should a piston stop in irreversible process? |
I measure the intensity and polarization of light emitted from a blood sample that contains excited fluorescein (experiment known as fluorescence polarization assay). The excitation is done, as usual, with vertically polarized light.
In case the sample has certain macromolecules of interest (an antibody, in this cas... |
The N-N bond length in N<sub>2</sub>O<sub>4</sub> is 1.64 Å which is much longer than in the case of Hydrazine N<sub>2</sub>H<sub>4</sub> (1.47 Å). This means that the bond is quite weak. Another unusual case I see that N-N bond length in N<sub>2</sub>O<sub>3</sub> ( the blue asymmetric form ) is 1.86 Å !!
That is ver... |
I measure the intensity and polarization of light emitted from a blood sample that contains excited fluorescein (experiment known as fluorescence polarization assay). The excitation is done, as usual, with vertically polarized light.
In case the sample has certain macromolecules of interest (an antibody, in this cas... |
Suppose we have an ideal gas filled inside a container fitted with piston.External pressure is equal to internal pressure.
Now if we suddenly decrease the external pressure, we say that the gas will expand till the internal pressure and external pressure become equal.
But shouldn't the gas expand beyond that poin... |
>I am conducting a school-based research project into the antioxidative properties of green tea. Part of the procedure is to determine the concentration of antioxidant in green tea. This antioxidant is EGCG (a type of *catechin*).
First of all, you cannot determine the concentration of just EGCG (epigallocatechin ga... |
I want to make a sample for proton NMR signal-to-noise-ratio measurement. It is conventional to use 1% ethylbenzene in *d*-chloroform, as specified [here](https://www.drugfuture.com/Pharmacopoeia/usp38/data/v38332/usp38nf33s2_c761.html).
I have two questions:
1) What is meant exactly, by 1% ethylbenzene? In some p... |
It would be interesting to know the sources cited in your question (both the book, as well as the primary literature) as reference because one complementary approach to the (assumed) spectroscopic determination is the analysis of the crystalline state. While there are multiple records about pure benzene, it seems ther... |
Suppose we have an ideal gas filled inside a container fitted with a piston. The external pressure is equal to internal pressure.
If we suddenly decrease the external pressure, we say that the gas will expand until the internal pressure and external pressure become equal.
Considering an irreversible process, shou... |
When does a piston stop in an irreversible process? |
[Chromium (VI) fluoride][1], also known as chromium hexafluoride is a possible chemical compound with a chromium atom attached to 6 fluorine atoms. It has been unsuccessfully synthesized a number of times by heating up chromium to 400 °C in a fluorine atmosphere at 20 megapascals of pressure and freezing it as it was f... |
> What is the sum of stoichiometric coefficients of redox reaction: $\ce{Cu2S + HNO3 -> S + NO2 + Cu(NO3)2 + H2O}$?
This exercise is from a multiple choice exam. I have balanced the equation:
$$\ce{1 Cu2S + 4 HNO3 -> 1 S + 2 NO2 + 1 Cu(NO3)2 + 2 H2O.}$$
Therefore I have calculated the sum of coefficients as $\su... |
How to balance the reaction equation between copper (I) sulfide and nitric acid? |
How to make 4-Cyclohexene-1,2-diol from Cyclohexa-1,4-diene? |
I see the questions of why a galvanic cell needs a salt bridge and why a electrolytic cell doesn't need a salt bridge being answered separately but I still can't grasp why you are not allowed to mix or interchange the reasons of the two. Can someone explain why both cells are set up in that way and provide a comparison... |
Why do galvanic cells need a salt bridge while electrolytic cells don't? |
[![enter image description here][1]][1]I know that RTG's use Radioactive Isotope that emit Alpha particles generally (ie. NASA uses Pu 238), I also know that these Alpha particles are consiting of 2 Protons and 2 Neutrons, since the RTG has two thermocouple plates that force the protons and the electrons to the cooler ... |
The following instructions are given for a preparation and I am wondering what it means to "shear an immulsion"?
> The water phase components and the oil phase components are each mixed
> in separate containers and filtered and the refractive index of each
> is measured. The refractive index of the water phase is ... |
What does it mean to "shear" an emulsion? |
The N-N bond length in N<sub>2</sub>O<sub>4</sub> is 1.64 Å which is much longer than in the case of Hydrazine N<sub>2</sub>H<sub>4</sub> (1.47 Å). This means that the bond is quite weak. Another unusual case I see that N-N bond length in N<sub>2</sub>O<sub>3</sub> ( the blue asymmetric form ) is 1.86 Å !!
That is ver... |
The $\ce{N-N}$ bond length in $\ce{N2O4}$ is $\pu{1.64 Å}$ which is much longer than in the case of Hydrazine $\ce{N2H4}$ $\pu{(1.47 Å)}$. This means that the bond is quite weak. Another unusual case I see that $\ce{N-N}$ bond length in $\ce{N2O3}$ ( the blue asymmetric form ) is $\pu{1.86 Å}$ !!
That is very weak... |
I have spent the last couple of days learning to navigate, find useful information and use the download service on the PubChem website. One of the pieces of information you can find is a chiral center count, but I can't seem to find anything about the chiral center location. <br />
This might just be something that is... |
Does PubChem have stereocenter location data? |
Here's the question
[![enter image description here][1]][1]
[![enter image description here][2]][2]
[1]: https://i.stack.imgur.com/aGHpZ.jpg
[2]: https://i.stack.imgur.com/ol3I3.jpg
For a reaction to take place the net energy should go down, and thus option (d) can be discarded.
We are now lef... |
How to select a schematic of the coordinate vs energy representing a rearrangement reaction? |
I have a question about a pH calculation which is the following:
Calculate the pH of $\pu{E-8 mol/L}~\ce{HCl}$ solution in water.
($\ce{HCl}$ is a strong acid which completely ionizes in water)
So what I had done:
1. completely ionizes in water so: $\pu{E-8 mol}~\ce{H+}$ is added to water.
2. Water equillib... |
I'm working on a lab report that has some specific questions that need to be included. The lab work itself dealt with GC–MS.
What is the effect of the temperature selected during cryofocusing/cryotrapping? What is the effect of making this temperature warmer or colder?
My understanding was that the gas based samp... |
What is the effect of temperature during cryotrapping? |
What is the percentage composition of diet coke? |
> A mixture of $\pu{1 g}$ of $\ce{H2(g)}$ and $\pu{1.06 g}$ $\ce{H2S(g)}$ in a $\pu{0.5 L}$ flask come to equilibrium at $\pu{1670 K}$. At equilibrium, there are $\pu{8\times10^{-6} mol}$ of $\ce{S2(g)}$ present. Determine $K_\mathrm{p}$?
I set up an ICE table:
$$\ce{2H2 +S2<=>2H2S}$$
\begin{array}{l|l|l} \hline
... |
> A mixture of $\pu{1 g}$ of $\ce{H2(g)}$ and $\pu{1.06 g}$ $\ce{H2S(g)}$ in a $\pu{0.5 L}$ flask come to equilibrium at $\pu{1670 K}.$ At equilibrium, there are $\pu{8E-6 mol}$ of $\ce{S2(g)}$ present. Determine $K_p.$
I set up an ICE table:
$$
\begin{array}{ccc}
\ce{&2 H2 &+ &S2 &<=> &2 H2S} \\
&\pu{1 M} && ... |
Question: (asked in class of online lecture, not from book)
>Two s orbitals can overlap or not as shown? [![enter image description here][1]][1]
Answer by sir : No because extent of overlapping should always be less than 50 %.
My answer and argument:
1. Practically the two spheres are not overlapping 50% ... |
Question: (asked in class of online lecture, not from book)
>Two s orbitals can overlap or not as shown? [![enter image description here][1]][1]
Answer by sir : No because extent of overlapping should always be less than 50 %.
My answer and argument:
1. Practically the two spheres are not overlapping 50% ... |
Question: (asked in class of online lecture, not from book)
>Two s orbitals can overlap or not as shown?  circles in diagram depict maximum probability region of $\ce{s -} $orbitals in ideal situation when atoms are not bonded. + Denotes nucleus.
... |
Two methods for chlorinating water are using chlorine gas $(\ce{Cl2})$ or calcium hypochlorite $(\ce{Ca(OCl)2}).$ By using chemical equations how can you predict the pH of the water brought about by the chlorinating process? |
1. In aqueous solution, chlorine can undergo disproportionation: one atom in $\ce{Cl2}$ (oxidation state $0$) is reduced to $\ce{Cl-}$ (oxidation state $-1),$ the other is oxidized to a species in which the chlorine atom has the oxidation state $+1.$
>!$$\ce{Cl2 + 3H2O -> 2H3O+ + Cl- + OCl-}$$
Ask yourself ... |
Question: (asked in class of online lecture, not from book)
>Two s orbitals can overlap or not as shown? circles in diagram depict maximum probability region of $\ce{s -} $orbitals in ideal situation when atoms are not bonded. P, Q Denotes nucleus.
... |
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