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Why are pi bonds formed only when sigma bonds are formed? |
I was wondering if there was any way of representing a dative/coordinate covalent bond on a chemical diagram.
A single bond can easily be represented as a single line, a double bond as a double line and a triple bond as a triple line.
Take the below structure of ethene, a compound with single and double non-coord... |
Is there any way of representing a dative/coordinate covalent bond? |
I was wondering if there was any way of representing a dative/coordinate covalent bond on a chemical diagram.
A single bond can easily be represented as a single line, a double bond as a double line and a triple bond as a triple line.
Take the below structure of ethene, a compound with single and double non-coord... |
> How to find equivalent weight of acid if given that 1.321 g acid reacts with magnesium to give 1.72 g salt?
I mean we have weight of metal divided by equivalent weight of metal = wt. of salt divided by equivalent weight of salt. If known salt is given (e.g. MgCl or MgSO4) we can find equivalent weight of salt. And... |
Given a mixture of $\ce{HCl}$ and $\ce{MCl3}$ and the following dissociation constants for $\ce{M(OH)3}$, how can the concentrations of $\ce{HCl}$ and $\ce{MCl3}$ be determined separately by titrating this solution with a standard strong base (say, 0.1M $\ce{NaOH}$) ? I want to be able to sketch the approximate titrati... |
How to analyze a acid and salt mixture using titrimetry? |
Why does this happen? |
> How to find equivalent weight of acid if given that 1.321 g acid reacts with magnesium to give 1.72 g salt?
I mean we have weight of metal divided by equivalent weight of metal = wt. of salt divided by equivalent weight of salt. If known salt is given (e.g. MgCl or MgSO4) we can find equivalent weight of salt. And... |
> How to find equivalent weight of acid if given that 1.321 g acid reacts with magnesium to give 1.72 g salt?
Four options are given:
1. 49
2. 36.5
3. 45
4. none of above.
The second choice is given as the answer.
> I tried to solve the question. I used the formula (wt. of acid)/(equivalent we... |
I was reading N.C.E.R.T. class XI part 2 book and chapter Hydrogen,when I came across this statement:
> Loss of the electron from hydrogen atom
results in nucleus ($\ce{H+}$) of ~1.510–3 pm size.
This is extremely small as compared to normal
atomic and ionic sizes of 50 to 200pm. As a
consequence, H+ does not ex... |
Why are hydrogen ions always associated with another molecule? |
> 1) Why is only triphenyl phosphine used here. Why not some stronger
> nucleophile like say trimethyl phosphine?
Trialkyl phosphines can particpate in the Wittig reaction just fine, but they create some other problems. Let's say you were going to create the phosphonium salt from ethyl iodide and trimethyl phosphi... |
I am currently investigating about the interaction behavior of few atoms in certain conditions.
So, is it possible to use the concept of single point energy to represent the atomic interaction energies or I have to go other way around ?
I was also wondering that what is the basic difference between potential en... |
![enter image description here][1]
[1]: https://i.stack.imgur.com/8fKfm.png
How do I relate the half life to the overall rate of reaction?
I argued that from the data, doubling the partial pressure of either reactant, keeping the other constant, will half the half life.
So try t1/2 =
$\frac{\ce{[1]}... |
> However, surely $P_j$ alone is dimensionless as it's a partial pressure defined by dividing a pressure by a pressure - leaving no units. How does that work? Or am I wrong by assuming that a partial pressure has no units?
You are wrong to assume that partial pressure has no units. Partial pressure has units of pre... |
![enter image description here][1]
[1]: https://i.stack.imgur.com/8fKfm.png
How do I relate the half life to the overall rate of reaction?
I argued that from the data, doubling the partial pressure of either reactant, keeping the other constant, will half the half life.
So try t1/2 =
$\frac{\ce{[1]}... |
Let me create background first.Oxidizing agent is the chemical that helps something else oxidize and itself gets reduced.(reduction in charge)
N in $\ce{HNO3}$ is in the +5 oxidation state.. how do we know that? H is +1, O is -2 and the overall $\ce{HNO3}$ has a zero net change.. And same goes for $\ce{H3PO4}$ resul... |
Ionic bonds seem to be intermolecular but are classified as chemical bonds.
> "Ionic bonding is a type of chemical bond that involves the electrostatic attraction between oppositely charged ions." - *Wikipedia, definition of an ionic bond*
> "The physical force of attraction which holds atoms and molecules in a ... |
I have asked a question loosely asking this, where I confused terms and did not specify what I wanted to know [here][1], so I formed a new question.
What are the differences and similarities between ionic bonds and covalent bonds and ionic bonds and dipole-dipole interactions?
It seems to be that an ionic bond is... |
Is an ionic bond more like a covalent bond or an intermolecular force? |
Let me create background first. Oxidizing agents are the chemical that helps something else oxidize and itself gets reduced.(reduction in charge)
$\ce{N}$ in $\ce{HNO3}$ is in the +5 oxidation state - how do we know that? $\ce{H}$ is +1, $\ce{O}$ is -2 and the overall $\ce{HNO3}$ has a zero net charge. The same goes... |
I am currently investigating about the interaction behavior of few atoms in certain conditions.
So, is it possible to use the concept of single point energy to represent the atomic interaction energies or I have to go other way around ?
I was also wondering that what is the basic difference between potential en... |
Experimentally it appears that increase in pressure, fuel concentration, and chain length causes AIT to decrease until a minimum where even further increase in these parameters increases the AIT. Additionally it seems that AIT is lowered by increasing the vessel volume.
[From the last page of this paper:][1]
>Seme... |
From what i understand, the standard reduction/oxidation potential table is based on the hydrogen half reaction which makes a reduction and oxidation potential of 0 respectfully. In a research internship I'm in now looking for more efficient batteries, they are basing potential candidates in respect with magnesium. My ... |
From what I understand, the standard reduction/oxidation potential table is based on the hydrogen half reaction which makes a reduction and oxidation potential of 0 respectfully.
In a research internship I'm in now, we are looking for more efficient batteries, they are basing potential candidates in respect with ma... |
In my textbook written that:
>Given that $K_\mathrm{sp}(\ce{Ag2CrO4})=9.0\times 10^{-12}$, consider the solubility of $\ce{Ag2CrO4}$ in a $0.100\:\mathrm{M}$ solution of $\ce{AgNO3}$.
>Initial concentrations (before any $\ce{Ag2CrO4}$ dissolves) are,
$[\ce{Ag+}]_0=0.100\:\mathrm{M}$ (from $\ce{AgNO3})$ and $[\ce... |
According to the law of equivalence, the number of equivalents of each reactant and product in a reaction are equal. Why is it so ? |
For example,
1-bromopropane + NaSH = Propanethiol + NaBr
vs
1-bromopropane + H2S = Propanethiol + HBr
Which is more valid, and why? or are they equally valid? |
When undergoing an SN rxn, does the other atom to which the nucleophile is ionically bonded matter (other than that it possess a positive charge)? |
For example,
1-bromopropane + $\ce{NaSH}$ = Propanethiol + $\ce{NaBr}$
vs
1-bromopropane + $\ce{H2S}$ = Propanethiol + $\ce{HBr}$
Which is more valid, and why? or are they equally valid? |
Peptide bond is synthesized when the carboxyl group of one aminoacid molecule reacts with the amino group of the other aminoacid molecule, causing the release of a molecule of water.
Water molecule consist of **hydroxyl from carboxyl group** and **hydrogen from amino group**.
And that's a bit strange to me since ... |
Carboxyl group behaves like base and amino group behaves like acid when creating peptide bond, right? |
Peptide bonds are synthesized when the carboxyl group of one aminoacid molecule reacts with the amino group of the other aminoacid molecule, causing the release of a molecule of water.
Water molecules consist of **hydroxyl from carboxyl group** and **hydrogen from amino group**.
And that's a bit strange to me sin... |
Do carboxyl groups behave like a base and amino groups behave like an acid when creating peptide bonds? |
> 1) Why is only triphenyl phosphine used here. Why not some stronger
> nucleophile like say trimethyl phosphine?
Trialkyl phosphines can particpate in the Wittig reaction just fine, but they create some other problems. Let's say you were going to create the phosphonium salt from ethyl iodide and trimethyl phosphi... |
> Which is more valid, and why?
**On paper, they are both valid but**
$\ce{H2S}$ is very toxic and corrosive, so the first method using sodium hydrosulfide would likely be preferred. However, in industry, where raw material cost is very important, both of these methods are successfully [used][1].
However bo... |
> When undergoing an SN rxn, does the other atom to which the
> nucleophile is ionically bonded matter?
It can matter. If the counterion shifts the covalent-ionic nature of the bond connecting it to the nucleophile, then the nucleophilicity of the nucleophile can change (increase or decrease). However in your exa... |
For example,
1-bromopropane + $\ce{NaSH ->}$ Propanethiol + $\ce{NaBr}$
*vs.*
1-bromopropane + $\ce{H2S ->}$ Propanethiol + $\ce{HBr}$
Which is more valid, and why? Or are they equally valid? |
> 1) Why is only triphenyl phosphine used here. Why not some stronger
> nucleophile like say trimethyl phosphine?
Trialkyl phosphines can particpate in the Wittig reaction just fine, but they create some other problems. Let's say you were going to create the phosphonium salt from ethyl iodide and trimethyl phosphi... |
You cannot define ‘vacuum’ oxidation potentials, or otherwise derive them *de novo* without having *some* zero-point. There is, technically, no self-suggesting zero-point around — unlike for example temperature, where $0\,\mathrm{K}$ is equivalent to ‘molecular movement frozen’.
Part of the reason is, that the elect... |
we must write empirical formula of CH3COOH as CH2O or COH2 ? Alike ? Any nomenclature? Somebody tell me it was because of bonding, different way of writing the chemical formula mean different way or bonding, but I'm not sure it is correct or not, please help |
Vinegar CH2O ? COH2 |
[This question about boiling milk][1] reminded me of my everyday lab work at the rotavap: Some solvents and solutes are feared for the intense bubbling they create while the solution is boiling — be it at ambient pressure like the milk or at reduced pressure in the rotavap. For most of the infamous solvents, the bubble... |
Why do some solvents bubble more than others when boiling? |
we must write empirical formula of $\ce{CH3COOH}$ as $\ce{CH2O}$ or $\ce{COH2}$ ? Alike ? Any nomenclature?
Somebody told me it was because of bonding, different way of writing the chemical formula mean different way or bonding, but I'm not sure if it is correct or not, |
Just wondering if there was a systematic way to identify an alkyl ligand as a $\pi$ acceptor or $\pi$ donor in a transition metal complex?
Although various sources indicate that weak field ligands are typically $\pi$ donors and strong field ligands are $\pi$ acceptors, I'm having trouble with the more uncommon liga... |
Recall the meaning of the half life $t_{1/2}$: At $t_{1/2}$, a concentration (or partial pressure) is decreased to the half of its initial value.
**It is crucial to realize that this represents exactly the $\mathbf{-\frac{dp_A}{dt}}$ in your rate equation!**
With other words, $-\frac{dp_A}{dt} = k\cdot p_A\cdot p... |
Why should the erlenmeyer flask used to store NaOH be dry? Why should it be kept covered at all times?
I googled and got nothing. |
Why should the Erlenmeyer flask used to store $\ce{NaOH}$ be dry? Why should it be kept covered at all times?
|
I have often wondered about diagonal relationships in the periodic table, and the most often cited explanations revolve around charge-density considerations.
But other than that what other factors could (possibly) contribute to this phenomenon? Would someone care to share a few hypothesises? |
I have often wondered about diagonal relationships in the periodic table, and the most often cited explanations revolve around charge-density considerations.
But other than that what other factors could (possibly) contribute to this phenomenon? Would someone care to share a few hypotheses? |
Why must NaOH be kept dry during storage? |
I have some molecular PDB structures with missing hydrogens. Is there a software available that places missing hydrogens and assigns a charge to the molecule that is reliable?
I have used Avogadro to add hydrogens (though I don't know how to compute the charge with it), but I've found that some hydrogens aren't well... |
Reliable automatic addition of hydrogens and charge assignment at given pH? |
I have some molecular PDB structures with missing hydrogens. Is there a software available that places missing hydrogens and assigns a charge to the molecule that is reliable?
I have used Avogadro to add hydrogens (though I don't know how to compute the charge with it), but I've found that some hydrogens aren't well... |
> While naming any compound, the numbering should be done such that position of substituted groups gives smallest sum.
I'm struggling with IUPAC naming for cyclic compounds. How exactly does one go about studying this? Perhaps I can make use of a source online? |
In medical shop I have seen that there are loads of vitamins tablets available but I was wondering like does vitamins in tablet are more efficient than the vitamins which are available in their natural source like in fruits ? |
Are vitamins in tablet are more efficient than the vitamins in their natural source? |
I have a molecule extracted from the PDB. When I load it into Avogadro, it's some misplaced bond types. I want to correct this, by setting the bond type (single, double) for these bonds. How can I do this? |
I have a molecule extracted from the PDB. When I load it into Avogadro, it has some misplaced bond types. I want to correct this, by setting the bond type (single, double) for these bonds. How can I do this? |
In my textbook, for calculating the percentage dissociation of $\ce{HF}$ for the given equation:
$$\ce{HF + H2O <-> H3O+ + F-}$$
The solution is:
Initial Concentrations
$$[\ce{HF}] = 0.08M, \: \ce{[H3O+]} = 0, \:\ce{[F- ]}= 0$$
Equilibrium concentrations
$$[\ce{HF}] = 0.08M - x, \: \ce{[H3O+]} = x, \:\ce{[F- ... |
What is the reason for water molecules $\ce{H_2O}$ being assymmetric while other molecules like $\ce{CO_2}$ being completely symmetric? See the pictures below:
![enter image description here][1]
![enter image description here][2]
In both case there is an electronegative difference between the atoms in the molecu... |
Why are H2O assymmetric while CO2 is not? |
In my textbook, for calculating the percentage dissociation of $\ce{HF}$ for the given equation:
$$\ce{HF + H2O <=> H3O+ + F-}$$
The solution is:
Initial Concentrations
$$[\ce{HF}] = 0.08~\mathrm{M}, \: \ce{[H3O+]} = 0, \:\ce{[F- ]}= 0$$
Equilibrium concentrations
$$[\ce{HF}] = 0.08~\mathrm{M} - x, \: \ce{[H3... |
I was given the formulas,
$$\begin{alignat}{2}
\ce{MnO4^2- \;&<=> MnO4- + e-}\quad &&E^\circ = -0.56\ \mathrm{V}\\
\ce{MnO2 + 2H2O \;&<=> MnO4^2- + 4H+ + 2e-}\quad &&E^\circ = -2.27\ \mathrm{V}
\end{alignat}$$
I gathered you have to see if it’s non-spontaneous or spontaneous and compare it with the original re... |
What is the reason for water molecules $\ce{H_2O}$ being asymmetric while other molecules like $\ce{CO_2}$ being completely symmetric? See the pictures below:
![enter image description here][1]
![enter image description here][2]
In both case there is an electronegative difference between the atoms in the molecul... |
Why are H2O asymmetric while CO2 is not? |
I think the reaction is essentially an incomplete combustion reaction.
In a vaporizer, the idea is to get the propylene glycol, glycerine, and and "flavor" molecules into the vapor phase (or into aerosol droplets) without chemically degrading them.
However, the way this is accomplished is with very high-temperatu... |
>Two quantities of water ($M_\mathrm{r}=18$) each of mass $216\ \mathrm{g}$ are mixed together in a
vessel. The temperatures of the two quantities before mixing are $303\ \mathrm{K}$ and $333\ \mathrm{K}$. The entire system is perfectly insulated and the vessel has a negligible heat capacity. Calculate the change in e... |
The hydrocarbon C17H36 can be cracked.
Which compound is the least likely to be produced in this reaction?
A C3H8 B C4H8 C C8H16 D C16H34
Is it D because cracking's purpose is the breaking of long hydrocarbon chains into smaller ones |
The hydrocarbon $\ce{C17H36}$ can be cracked.
Which compound is the least likely to be produced in this reaction?
>A: $\ce{C3H8}$ <br>B: $\ce{C4H8}$ <br>C: $\ce{C8H16}$ <br>D: $\ce{C16H34}$
Is it D because cracking's purpose is the breaking of long hydrocarbon chains into smaller ones |
Least likely product of a hydrocarbon cracking reaction? |
Hi, I'm Manish.
I've been with Chem.SE from the start, and am really happy to see how far it's reached!
I was at odds with myself whether or not I should stand in this election but it occurred to me that I'll never have the time to contribute content to this site; moderation is the way I think I can help best!
... |
Consider the following:
PbS(s) + 1.5O2(g) = PbO(s) + SO2(g) dH°= -413.7 kJ
PbO(s) + C(s) = Pb(s) + CO(g) dH° = +106.8 kJ
a. Calculate the enthalpy of the following process:
PbS(s) + 1.5O2(g) + C(s) = Pb(s) + SO2(g) + CO(g)
b. What is the energy needed to make 454g of PbS ino Pb? |
I have often wondered about diagonal relationships in the periodic table, and the most often cited explanations revolve around charge-density considerations.
But other than that what other factors could (possibly) contribute to this phenomenon? Would someone care to share a few hypotheses?
**EDIT** It was sugge... |
There are two ways to look at this question. One is simple carbon atom counts. Another is the saturation of the products.
**Carbon atom counts**. The question doesn't specify which of the 24894 isomers of heptadecane is to be cracked. Suppose it is "normal" or _n_-heptadecane. Cracking usually begins with th... |
There are two ways to look at this question. One is simple carbon atom counts. Another is the saturation of the products.
**Carbon atom counts**. The question doesn't specify which of the 24894 isomers of heptadecane is to be cracked. Suppose it is "normal" or _n_-heptadecane. Cracking usually begins with th... |
Consider the following:
$\ce{PbS(s) + 1.5O2(g) -> PbO(s) + SO2(g)}$ dH°= -413.7 kJ
$\ce{PbO(s) + C(s) -> Pb(s) + CO(g)}$ dH° = +106.8 kJ
a. Calculate the enthalpy of the following process:
$\ce{PbS(s) + 1.5O2(g) + C(s) = Pb(s) + SO2(g) + CO(g)}$
b. What is the energy needed to make 454g of $\ce{PbS}$ int... |
Consider the following:
$\ce{PbS(s) + 1.5O2(g) -> PbO(s) + SO2(g)}$ dH°= -413.7 kJ
$\ce{PbO(s) + C(s) -> Pb(s) + CO(g)}$ dH° = +106.8 kJ
a. Calculate the enthalpy of the following process:
$\ce{PbS(s) + 1.5O2(g) + C(s) = Pb(s) + SO2(g) + CO(g)}$
b. What is the energy needed to make 454g of $\ce{PbS}$ int... |
Consider the following:
$\ce{PbS(s) + 1.5O2(g) -> PbO(s) + SO2(g)}$ dH°= -413.7 kJ
$\ce{PbO(s) + C(s) -> Pb(s) + CO(g)}$ dH° = +106.8 kJ
a. Calculate the enthalpy of the following process:
$\ce{PbS(s) + 1.5O2(g) + C(s) = Pb(s) + SO2(g) + CO(g)}$
b. What is the energy needed to make 454g of $\ce{PbS}$ int... |
Consider the following:
$\ce{PbS(s) + 1.5O2(g) -> PbO(s) + SO2(g)}$ dH°= -413.7 kJ
$\ce{PbO(s) + C(s) -> Pb(s) + CO(g)}$ dH° = +106.8 kJ
a. Calculate the enthalpy of the following process:
$\ce{PbS(s) + 1.5O2(g) + C(s) = Pb(s) + SO2(g) + CO(g)}$
b. What is the energy needed to make 454g of $\ce{PbS}$ int... |
Consider the following:
$\ce{PbS(s) + 1.5O2(g) -> PbO(s) + SO2(g)}$ dH°= -413.7 kJ
$\ce{PbO(s) + C(s) -> Pb(s) + CO(g)}$ dH° = +106.8 kJ
a. Calculate the enthalpy of the following process:
$\ce{PbS(s) + 1.5O2(g) + C(s) = Pb(s) + SO2(g) + CO(g)}$
b. What is the energy needed to make 454g of $\ce{PbS}$ int... |
Cooking oil that jumps from a frying pan in use and over time accumulates around the frying pan on a wooden surface is sticky and hard to remove.
My question is why. Why is it hard to remove? What is the chemistry behind it? Does it bond with the wood somehow? If so, how is it different from oil used to give the woo... |
Why is grease from cooking hard to remove from wood? |
#13 , i tried finding the slope between two points but I keep getting wrong values, how do you find the initial rate?
![enter image description here][1]
[1]: https://i.stack.imgur.com/LtYR3.jpg |
initial rate of reaction from the graph? |
#13 , I tried finding the slope between two points but I keep getting wrong values, how do you find the initial rate?
![enter image description here][1]
[1]: https://i.stack.imgur.com/LtYR3.jpg |
Initial rate of reaction from the graph? |
#13 , I tried finding the slope between two points but I keep getting wrong values, how do you find the initial rate?
So I started by trying to find a slope of two points. (0,0.4) and (10,0.2) after finding it i get -0.02 which is the opposite of the right answer in sign. I tried to check myself by trying to find ... |
What is its structure?
I found an image of $\ce{B6O11}$ unit but it looks incorrect:
![unit][1] The top left corner one.
1. The oxygen can make max 2 bonds but $\ce{O8}$ has three!
2. There are six oxygen with only one bond, that is the unit has -6 net charge but $\ce{2Ca^{2+}... |
There is a container that has a volume of 5L on one side and 3L on the other and is separated in the middle. There are 2 mols of N2 on one side at 0 degrees C and 4 mols of H2 on the other at 0 degrees C. When the valve is turned and the gases react, what will the total pressure be?
The balanced reaction is N2+ 3H2= 2... |
There is a container that has a volume of 5L on one side and 3L on the other and is separated in the middle. There are 2 mols of $\ce{N2}$ on one side at 0 degrees C and 4 mols of $\ce{H2}$ on the other at 0 degrees C. When the valve is turned and the gases react, what will the total pressure be?
The balanced reaction... |
There is a container that has a volume of 5L on one side and 3L on the other and is separated in the middle. There are 2 mols of $\ce{N2}$ on one side at 0 degrees C and 4 mols of $\ce{H2}$ on the other at 0 degrees C. When the valve is turned and the gases react, what will the total pressure be?
The balanced reaction... |
![enter image description here][1]
[1]: https://i.stack.imgur.com/IQpRF.jpg
ATTEMPT:
In DMSO (Di-Methyl Sulphoxide), there is no acidic hydrogen. So negative charge on Oxygen will be concentrated as the anion will not be solvated by the polar aprotic solvent.Hence it should act as a strong nuclephilic centre... |
![enter image description here][1]
[1]: https://i.stack.imgur.com/IQpRF.jpg
ATTEMPT:
In DMSO (Di-methyl sulphoxide), there is no acidic hydrogen. So negative charge on oxygen will be concentrated as the anion will not be solvated by the polar aprotic solvent. Hence it should act as a strong nuclephilic centr... |
It seems like you have the right idea to me,
For the "Initial Rate," you're taking a curve and doing a straight approximation of the curve over a small portion, as you appear to be doing.
Your logic also appears correct to me, a decrease in concentration should correspond to a negative rate.
My guess is that ... |
It seems like you have the right idea to me,
For the "Initial Rate," you're taking a curve and doing a straight approximation of the curve over a small portion, as you appear to be doing.
Your logic also appears correct to me, a decrease in concentration should correspond to a negative rate.
My guess is that ... |
> There is a container that has a volume of $5~\mathrm{L}$ on one side and $3~\mathrm{L}$ on the other and is separated in the middle. There are $2~\mathrm{mol}$ of $\ce{N2}$ on one side at $0~^\circ\mathrm{C}$ and $4~\mathrm{mol}$ of $\ce{H2}$ on the other at $0~^\circ\mathrm{C}$. When the valve is turned and the gase... |
How to calculate the equilibrium pressure when ammonia and hydrogen gasses react in a closed system? |
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