instruction stringlengths 15 21.8k |
|---|
How do I find the ratio in which the residue of a reaction combines with HCl? |
>Which of the following isn't an elementary substance?
>
> 1. Ozone
> 2. Sulfur
> 3. diamond
> 4. quartz
I don't get what **elementary substance** means.
By seeing the options and the word elementary, I guess it means something like pure or obtained in its original form. |
> Larger the difference in electronegativities of bonded atoms, the larger the dipole moment.
(this statement has been extracted from [chemwiki-dipole moment](http://chemwiki.ucdavis.edu/Physical_Chemistry/Quantum_Mechanics/Atomic_Theory/Intermolecular_Forces/Dipole_moments))
The electronegativity differen... |
I am solving some problems involving the order of dipole moments of some compounds. I could solve most of them but the following:
> Which has greater dipole moment?
> 1. $\ce{CH3F}, \ce{CH_3Cl}$
>
> 2.
> [![enter image description here][1]][1]
Since fluorine is more electronegative my assumption was that... |
**Part 1:** According to what I've learned so far, helium is in the first row of the periodic table, so its $n$ should always equal $1$. However, a question in my text asks about helium 2s. What is helium 2s? If helium 2s exists, why does the periodic table list helium in the first row instead of the second?
**Part ... |
I found out the answer is that
> with increase in branching, the molecules attain a spherical shape with less surface area. As a result, interparticle forces become weaker resulting in lower boiling point.
My problem is that if it attains a spherical shape then how is its surface area less because sphere has the... |
I am going to do an electroplating experiment, whereby I will be using a **Cu(NO3)2** solution to plate onto a cathode.
What is an easily accessible cathode which I can use for this? Would a **strip of Ag (s)** be sufficient, since it is a weaker reducing agent than Cu(s), and should therefore not react with any of th... |
What is a suitable material for a cathode in electroplating experiment? |
User Buck Thorn writes here that
> In chemistry we are most often interested in the effect of changes in $T$ or $P$ on $\Delta G$ for some process such as a phase change or chemical reaction which is otherwise carried out at constant $T$ and $P$.
See third answer here:
https://chemistry.stackexchange.com/questi... |
Are the derivations on $\Delta G$ consistent with Entropy interpretation? |
Are the derivations on Gibbs Free Energy consistent with the interpretation of entropy? |
X rays are produced when accelerated cathode rays strike a metal target or a metal anode.But how can we find the angle at which the x ray is emitted from the metal anode or the target when the cathode ray strikes the metal perpendicular to the surface?
Any suggestions?? |
What is the angle in which x rays are emitted from metal when the accelerated cathode rays are impacted perpendicular to the metal? |
Why is monohydrogen phosphate an incorrect name? |
Considering that the two quantities are linked by reality, how can be both imposed by independent definitions?
I am aware that the change taking place next May does not effect common weighing in chemistry and engineering, but still the new definition of mole (an exact number of entities, to be called Avogadro number ... |
User Buck Thorn writes here that
> In chemistry we are most often interested in the effect of changes in $T$ or $P$ on $\Delta G$ for some process such as a phase change or chemical reaction which is otherwise carried out at constant $T$ and $P$.
See third answer here:
https://chemistry.stackexchange.com/questi... |
User Buck Thorn writes here that
> In chemistry we are most often interested in the effect of changes in $T$ or $P$ on $\Delta G$ for some process such as a phase change or chemical reaction which is otherwise carried out at constant $T$ and $P$.
See third answer here:
https://chemistry.stackexchange.com/questi... |
I'm looking for a way to treat the surface of borosilicate glassware such that it won't contaminate solutions of puriss reagents in conditions that pure SiO2 wouldn't, yet keep the bulk physical properties (and low cost) of standard borosilicate glassware.
What are appropriate ways (i.e. without etching or contamina... |
Appropriate ways to remove Al from the Surface of Glass? |
User Buck Thorn writes [here](https://chemistry.stackexchange.com/a/103840/16683) that
> In chemistry we are most often interested in the effect of changes in $T$ or $P$ on $\Delta G$ for some process such as a phase change or chemical reaction which is otherwise carried out at constant $T$ and $P$.
Does this m... |
Are the derivations on Gibbs free energy consistent with the interpretation of entropy? |
I have a question about exercise 2.1 in Szabo and Ostlund's *Modern Quantum Chemistry*, which concerns the inner product between different spin orbitals: $\require{begingroup}\begingroup\newcommand{\br}{\mathbf{r}}\newcommand{\bx}{\mathbf{x}}$
> **Exercise 2.1.** Given a set of $K$ orthonormal spatial functions, $\{... |
> 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:
$$
\begin{array}{ccc}
\ce{& &2 H2 &+ &S2 &<=> &2 H2S} \\
\text{Initi... |
Consider the following conproportionation reaction:
$$\ce{NH4NO3 -> N2}$$
How would I go about balancing this using the half reaction/ion-electron method? |
> Air contains 20 % $\ce{O2}$ by volume. How many cm³ of air will be required
> for oxidation of 100 cm³ of acetylene?
>
>(a) 1064 cm³
(b) 212.8 cm³
(c) 500 cm³
(d) 1250 cm³
**Answer: (d)**
My solution:
Equation: $\ce{2C2H2 +5O2 -> 4CO2 +2H2O}$
From stoichiometric calculations:
* 2 moles of ... |
Air contains 20 % O2 by volume. How many cm³ of air will be required for oxidation of 100 cm³ of acetylene? |
I'm looking for a way to treat the surface of borosilicate glassware such that it won't contaminate solutions of puriss reagents in conditions that pure $\ce{SiO2}$ wouldn't, yet keep the bulk physical properties (and low cost) of standard borosilicate glassware.
What are appropriate ways (i.e. without etching or co... |
Appropriate ways to remove aluminum from the surface of glass? |
I am working on a project where one of the goals is to store data from computational quantum chemistry calculations for later retrieval.
Currently, we are trying to store the outcomes of simple bond (or angle or dihedral angle) "scan jobs". The main problem we have is in finding a way to represent the scan coordina... |
I'm not an expert, but as far as I understood a sugar solution is completely neutral since sugar can't take hydrogen ions out of the water or donate them in. Sugar is a non ionic compound, so it does not release H and OH ions in the water so it will not make the solution acidic or alkaline.
I keep on reading and see... |
This compound of uranium called [uranium hexoxide][1] is a special type of uranium oxide. The uranium should have an oxidation state of +12 ,the highest of any known chemical. The closest is the $\ce{[IrO4]+}$ cation with iridium having an oxidation state of +9 so this is obviously insane if this potentially exists. I... |
I was learning about Bent's Rule. I came across a formula
$$\cos\theta = \frac{s}{s-1}$$.
I am quite confused about θ. I know that it represents bond angle. But for a compound like $\ce{PCl5}$, which bonds angle has to be considered? For the equitorial bonds, θ = 2π/3 was used and θ = π/2 was used for axial bonds... |
What is θ in Bent's rule equation (%s - character)? |
I have 126.39 L of water. What volume of methane gas would I need to combust to heat it (at room temp, 21 degrees Celsius) to 38 degrees Celsius? How much $\ce{CO2}$ gas would be produced?
I calculated the molar enthalpy of combustion of methane and got −890.27 kJ/mol, and I know that factors into my calculation. I'... |
>Calculate the heat produced when a strip of $\ce{Mg}$ metal with a mass of $\pu{0.0801 g}$ is reacted with $\pu{50.0 ml}$ of $\pu{1.0 M}$ $\ce{HCl}$ to raise the temperature of water to $\pu{7.6^\circ C}$ (change in temp. = $\pu{7.6^\circ C}$). Calculate the heat produced when a mole of this metal is used.
I have t... |
What catalysts can be used to decompose nitrous oxide (N2O)? |
>Calculate the heat produced when a strip of $\ce{Mg}$ metal with a mass of $\pu{0.0801 g}$ is reacted with $\pu{50.0 ml}$ of $\pu{1.0 M}$ $\ce{HCl}$ to raise the temperature of the water by $\pu{7.6^\circ C}$ (change in temp. = $\pu{7.6^\circ C}$). Calculate the heat produced when a mole of this metal is used.
I ha... |
Does helium have a 2s orbital? |
I was learning about Bent's Rule. I came across a formula
$$\cos\theta = \frac{s}{s-1}$$
I am quite confused about θ. I know that it represents bond angle. But for a compound like $\ce{PCl5}$, which bonds angle has to be considered? For the equatorial bonds, θ = 2π/3 was used and θ = π/2 was used for axial bonds.... |
X rays are produced when accelerated cathode rays strike a metal target or a metal anode.
How can we find the angle at which the X-ray is emitted from the metal anode or the target when the cathode ray strikes the metal perpendicular to the surface?
Does anyone know why?
|
How to find the angle of emission of an X-ray during impact of accelerated cathode rays? |
Do azeotropes evaporate, without boiling, in proportionate amounts, or does this property describe their behaviour only at boiling point?
Concretely, if 91% isopropyl alcohol/water (by volume, i.e. an azeotropic mixture) is left open at say 25C, will it remain in that proportion as it evaporates, or become more dilu... |
Do azeotropic mixtures evaporate proportionally? |
I was learning about Bent's Rule. I came across a formula
$$\cos\theta = \frac{s}{s-1}$$
I am quite confused about $\theta$. I know that it represents bond angle. But for a compound like $\ce{PCl5}$, which bonds angle has to be considered? For the equatorial bonds, $\theta = 2 \pi/2$ was used and $\theta = \pi/2$... |
Consider the following comproportionation reaction:
$$\ce{NH4NO3 -> N2}$$
How would I go about balancing this using the half reaction/ion-electron method? |
I'm not an expert, but as far as I understood a sugar solution is completely neutral since sugar can't take hydrogen ions out of the water or donate them in. Sugar is a non ionic compound, so it does not release H and OH ions in the water so it will not make the solution acidic or alkaline.
I keep on reading and see... |
> Calculate the heat produced when a strip of $\ce{Mg}$ metal with a mass of $\pu{0.0801 g}$ is reacted with $\pu{50.0 ml}$ of $\pu{1.0 M}$ $\ce{HCl}$ to raise the temperature of the water by $\pu{7.6 °C}$ (change in temperature is $\pu{7.6 °C})$ Calculate the heat produced when a mole of this metal is used.
I have ... |
I am curious whether the modern Greek names for chemical elements were adopted from Classical Greek, both Latin and Classical Greek, or some international standard?
*I'm unsure if this is the correct place to address this question as there's no Greek SE site and meta seems a bit open ended about it.* |
Are the names for chemical elements the same in both modern Greek and classical Greek? |
What catalysts can be used to decompose nitrous oxide? |
Do azeotropes evaporate without boiling, in proportionate amounts or does this property describe their behaviour only at boiling point?
Concretely, if 91% isopropyl alcohol/water by volume, i.e. an azeotropic mixture is left open at say 25°C, will it remain in that proportion as it evaporates, or become more dilute ... |
As a lifelong New York Times crossword puzzler, I was baffled by clue 38-Across in today's puzzle (Saturday, May 22, 2021). The solution is a 6-letter word, and the clue is:
>Electrically balanced, in chemistry
The word that comes to my mind is "neutral." The accepted answer is "apolar," a word I've never heard o... |
New York Times Crossword: Is "electrically balanced" in chemistry "apolar" (given), "neutral," or something else entirely? |
Do azeotropes evaporate, without boiling, in proportionate amounts, or does this property describe their behaviour only at boiling point?
Concretely, if 91% isopropyl alcohol/water (by volume, i.e. an azeotropic mixture) is left open at say 25C, will it remain in that proportion as it evaporates, or become more dilu... |
Do azeotropes evaporate, without boiling, in proportionate amounts, or does this property describe their behaviour only at boiling point?
Concretely, if 91% isopropyl alcohol/water (by volume, i.e. an azeotropic mixture) is left open at say 25°C, will it remain in that proportion as it evaporates, or become more dil... |
Do azeotropes evaporate, without boiling, in proportionate amounts, or does this property describe their behaviour only at boiling point?
Concretely, if 91% isopropyl alcohol/water (by volume, i.e. an azeotropic mixture) is left open at say 25°C, will it remain in that proportion as it evaporates, or become more dil... |
This compound of uranium called [uranium hexoxide][1] or uranium (XII) oxide is a theoretical chemical compound. The uranium should have an oxidation state of +12 ,the highest of any known chemical. The closest is the $\ce{[IrO4]+}$ cation with iridium having an oxidation state of +9 so this is obviously mind blowing.... |
How many transition elements are there? |
Considering that the two quantities are linked by reality, how can be both imposed by independent definitions?
I am aware that the change taking place next May does not effect common weighing in chemistry and engineering, but still the new definition of mole (an exact number of entities, to be called Avogadro numbe... |
I understand that the Nernst Potentials $V=k_BT/e \ln c_o/c_i$ for all Ions in and outside of a cell barely change for when an AP travels along the cell bc barely any ions transverse the membrane compared to the amount of ions present. However the membrane potential obviously has an enormous change of 100mV.
Can som... |
How does the membrane potential change so drastically for an AP if the Nernst potentials don't? |
It should make sense that phosphorus has the positive charge,and gold itself
should have the negative charge in gold phosphide(and for any other gold phosphides) because phosphorus has a lower electronegativity than gold (phosphorus is 2.19, gold is 2.54),but then, they can both just share electrons. Is this true or... |
Would gold have the negative charge in gold phosphides? |
Do azeotropes evaporate, without boiling, in proportionate amounts, or does this property describe their behaviour only at boiling point?
Concretely, if 91% isopropyl alcohol/water (by volume, i.e. an azeotropic mixture) is left open at say 25 °C, will it remain in that proportion as it evaporates, or become more di... |
I understand that religious discussion is not want is wanted here, but it's just the pretext to my question that's religious based. I recently decided to read the Apocrypha. Sounded interesting. Anyway, when I got to The Book of Bel and The Dragon, there was this verse, which struck me as particularily interesting: 1:2... |
Can Someone Explain How This Is Possible? |
I understand that religious discussion is not wanted here, but it's just the pretext to my question. I recently decided to read the Apocrypha. Sounded interesting. Anyway, when I got to The Book of Bel and The Dragon, there was this verse, which struck me as particularly interesting:
>1:27 Then Daniel took pitch, a... |
Ancient explosive mixture? |
I understand that religious discussion is not wanted here, but it's just the pretext to my question. I recently decided to read the Apocrypha. Sounded interesting. Anyway, when I got to [The Book of Bel and The Dragon](https://en.wikipedia.org/wiki/Bel_and_the_Dragon), there was this verse, which struck me as particula... |
Is this ancient explosive mixture mentioned in the Apocrypha plausible? |
I understand that the Nernst potentials
$$V = \frac{k_\mathrm{B}T}{e} \ln\left(\frac{c_\mathrm{out}}{c_\mathrm{in}}\right)$$
for all ions inside and outside a cell barely change when an action potential travels along the cell, because barely any ions transverse the membrane compared to the amount of ions present.... |
How does the membrane potential change so drastically during an action potential? |
In your question, you have mentioned:
>The closest reaction I can find is Lossen rearrangement but in that hydroxyamic acid is first converted to its derivative but how will that be possible here?
You have recognized the reaction correctly but the Lossen rearrangement is the conversion of a hydroxamate ester to a... |
In your question, you have mentioned:
>The closest reaction I can find is Lossen rearrangement but in that hydroxyamic acid is first converted to its derivative but how will that be possible here?
You have recognized the reaction correctly but the Lossen rearrangement is the conversion of a hydroxamate ester to a... |
In your question, you have mentioned:
>The closest reaction I can find is Lossen rearrangement but in that hydroxyamic acid is first converted to its derivative but how will that be possible here?
You have recognized the reaction correctly but the Lossen rearrangement is the conversion of a hydroxamate ester to a... |
For example, given you had a molecule with a carboxyl functional group on either side, could it form a continuous chain of dimers? I understand this may not fit under the definition for polymer but I lack better terminology to describe such a thing. |
Could a 'polymer' be formed by hydrogen bonding? |
For example, given you had a molecule with a carboxyl functional group on either side, could it form a continuous chain of dimers? I understand this may not fit under the definition for polymer but I lack better terminology to describe such a thing.[![Carboxyl Dimer Polymer][1]][1]
[1]: https://i.stack.imgur.com... |
For example, given you had a molecule with a carboxyl functional group on either side, could it form a continuous chain of dimers? I understand this may not fit under the definition for polymer but I lack better terminology to describe such a thing. For Example:[![Carboxyl Dimer Polymer][1]][1]
Alternatively;[![Al... |
In propane, for example, the hydrogen bonds in displayed formula are shown with straight vertical line and horizontal lines. But in propene the hydrogen bonds near c=c are bent. Is it a rule that the hydrogen bonds near c=c are always bend? Or is there a reason? I am new to organic chemistry so I am having this confusi... |
>[![enter image description here][1]][1]
I am trying to figure out the product of this reaction. I initially thought that a carbocation would be formed at where the chlorine leaves
from:<br>
>[![enter image description here][2]][2] <br>
But according to the answer stated by the textbook, it should be this:
>... |
Why does this carbocation undergo further rearrangement? |
Since you are asking for a theoretical explanation, I believe a theoretical calculation might be helpful. It is possible to calculate the partial charges on atoms using electronic structure programs. I have calculated the partial charges at $\text{B3LYP/pcseg-1//GFN2-xTB}$ level (with GAMESS and xTB).
### $\ce{Me-\o... |
Since you are asking for a theoretical explanation, I believe a theoretical calculation might be helpful. It is possible to calculate the partial charges on atoms using electronic structure programs. I have calculated the partial charges at $\text{B3LYP/pcseg-1//GFN2-xTB}$ level (with GAMESS and xTB).
### $\ce{Me-\o... |
> State the hybridisation of asterisked carbon in $\ce{CH3-CH=C^{✪}=CH2}$
I am not sure between $\ce{sp^2}$ and $\ce{sp}$ hybridization. Because of the presence of double bonds I think it should be $\ce{sp^2}$ but because of the two $ \pi$- bonds I think $\ce{sp}$.
So which one is correct?
|
In my textbook, as examples of delocalization of pi electrons, benzene and nitrate ion have been considered. Benzene, due to symmetry of its resonating structures is simple enough. We assume that $\sigma$ electrons are localized and $\pi$ electrons are delocalized in the ring.
Each carbon atom promotes one electron... |
What is the hybridization of the central carbon in CH3-CH=C*=CH2? |
In my textbook, as examples of delocalization of pi electrons, benzene and nitrate ion have been considered. Benzene, due to symmetry of its resonating structures, is simple enough. We assume that $\sigma$ electrons are localized and $\pi$ electrons are delocalized in the ring.
Each carbon atom promotes one electro... |
> State the hybridisation of asterisked carbon in $\ce{CH3-CH=\overset{\ast}{C}=CH2}.$
I am not sure between $\mathrm{sp^2}$ and $\mathrm{sp}$ hybridization. Because of the presence of double bonds I think it should be $\mathrm{sp^2},$ but because of the two π-bonds I think $\mathrm{sp}$.
Which one is correct? |
What is the hybridization of the central carbon in buta‐1,2‐diene? |
Benzene and nitrate ion are given in my textbook as examples for the delocalization of π-electrons. Benzene, due to symmetry of its resonating structures, is simple enough. We assume that σ-electrons are localized and π-electrons are delocalized in the ring.
Each carbon atom promotes one electron from its $\mathrm{... |
At school, I did an experiment of synthesizing resorcinol-formaldehyde resin. When I added NaOH and gave some heat, the color of resorcinol-formaldehyde resin inside the test tube became reddish-brown. Can anyone tell me why? |
In the book Chemistry: The Central Science, they introduced 5 types of two-dimensional lattices like this:[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/XGAWS.png
The book said that the blue square represents the unit cell, the black dots are lattice points, and the vector a and b are ... |
When we talk about systems at constant temperature and pressure, maximum amount of non-PV work can be extracted if process is carried reversibly and in that case it is equal to change in Gibbs energy of the system (decrease in Gibbs energy if system does non - PV work, A.K.A work is extracted from system). When we have... |
[![enter image description here][1]][1]
well I was doing some questions and I have a bit of confusion
how do I decide which adjacent hydrogen gets attracted by $HSo4-$ ????
[![enter image description here][2]][2]
now we have 3 possibilities
[![enter image description here][3]][3]
[1]: https:/... |
I have stumbled upon [these instructions][1] on how to create $\ce{ZnO}$ nanoparticles.
I am interested in making a DIY ink, for use with a parallel metal plate pen and a piezo-actuated microdrop nozzle.
My question is:
What is a reasonable way of controlling the viscosity of such an ink? Is it possible to rep... |
How to modify viscosity of ZnO ink? |
In the book Chemistry: The Central Science, they introduced 5 types of two-dimensional lattices like this:[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/XGAWS.png
The book said that the blue square represents the unit cell, the black dots are lattice points, and the vector a and b are ... |
Why are there exactly 5 types of two-dimensional lattices, and what distinguishes them? |
In propane, for example, the hydrogen bonds in displayed formula are shown with straight vertical line and horizontal lines. But in propene the hydrogen bonds near $\ce{C=C}$ are bent. Is it a rule that the hydrogen bonds near $\ce{C=C}$ are always bend? Or is there a reason? I am new to organic chemistry so I am havin... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.