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It makes sense that
water-soluble salt when dissolved in water, they conduct electricity. Then when using the old method of the Volta Battery(using copper and zinc) with a different water-soluble salt dissolved in water, can it make electricity too?
Plus, If I use a ammeter to check its current, then does all of the... |
In an online test, the following question was asked:
[![enter image description here][1]][1]
The answer to this question was:
[![enter image description here][2]][2]
I totally agree with the answer, as $\ce{OCH_3}$ is an EDG, hence it will tend to form meta product in this reaction.
While reading [NAS](h... |
In my undergraduate Mechanisms-class the formation of tetranitromethane from acetic Anhydride with fuming $\ce{HNO3}$ was listed as optional knowledge in a chapter about the reactions of enols, enamines, etc. I can't find it in my notes or in the recommended literature, neither can I find information on molbase, and th... |
In an online test, the following question was asked:
[![enter image description here][1]][1]
The answer to this question was:
[![enter image description here][2]][2]
I totally agree with the answer, as $\ce{OCH_3}$ is an EDG, hence it will tend to form meta product in this reaction.
<hr />
While reading... |
Consider the metal carbonyl, pentacarbonyl iron(0). There exists synergic bonding between the central metal atom, iron and the neutral carbonyl ligands. This strengthens the metal-ligand bond but because electron density from the filled orbitals of the Iron atom is pushed into the anti bonding orbital of the $\ce{C-O}$... |
With the Thermo-Fisher Fusion Orbitrap mass spectrometer I can do both CID (collision-induced dissociation) and HCD (higher energy C trap dissociation) collision-induced dissociation studies.
When I apply HCD on inorganic molecules I observe more fragmentation products than with just CID suggesting multiple fragmen... |
I have been trying to balance this chemical reaction in an "acidic" medium without using oxidation number or ion electron method:[ Fe^2+ + Cr2O7 ----> Cr^3+ + Fe^3+ ] though I can balance number of atoms on both the sides [ Fe^2+ + Cr2O7 + 14H+ ----> 2 Cr^3+ + Fe^3+ 7 H2O ] but charge is still unbalanced, nd I am not... |
Why do we need to use oxidation number in order to balance a complex chemical reaction easily in an acidic or alkaline medium? |
> Can the Volta Battery use a different ionic solution?
Yes you can use any soluble salt as long as it does not react with electrodes, and certainly such a battery would be able to produce current. My chemistry high school teacher had a clock which ran on salt water. See for example, https://science.howstuffworks.co... |
I have been trying to balance this chemical reaction in an "acidic" medium without using oxidation number or ion electron method: [$\ce{Fe^2+ + Cr2O7 -> Cr^3+ + Fe^3+}$].
Though I can balance number of atoms on both the sides $[\ce{Fe^2+ + Cr2O7 + 14H+ -> 2 Cr^3+ + Fe^3+ 7 H2O}]$, but charge is still unbalanced. I a... |
I would like to know if there is a proper way to get the 3D information from a [SMILES][1] string.
1. Is there a standard way to embed a SMILES string in 3D space?
2. Are there other representations of compounds which include their spatial information too?
[1]: https://en.wikipedia.org/wiki/Simplified... |
A balanced equation must have a mass balance i.e., the masses should be equal on both sides and charges must be balanced as well. Oxidation number is just a way of book-keeping. Nothing fundamental there.
> Blockquote $[\ce{Fe^2+ + Cr2O7 + 14H+ -> 2 Cr^3+ + Fe^3+ 7 H2O}]$
What are you forgetting? It is mass balan... |
I have been trying to balance this chemical reaction in an "acidic" medium without using oxidation number or ion electron method: [$\ce{Fe^2+ + Cr2O7 -> Cr^3+ + Fe^3+}$].
Though I can balance number of atoms on both the sides $[\ce{Fe^2+ + Cr2O7 + 14H+ -> 2 Cr^3+ + Fe^3+ + 7 H2O}]$, but charge is still unbalanced. I... |
In an online test, the following question was asked:
[![enter image description here][1]][1]
The answer to this question was:
[![enter image description here][2]][2]
I totally agree with the answer, as $\ce{OCH_3}$ is an EDG, hence it will tend to form meta product in this reaction.
<hr />
While reading... |
This is one of the exam questions I got, but I don't understand how I'm supposed to answer *question* *b* without the concentration, I also didn't get a mass or volume so I can't calculate it using the molar mass. I tried using the formula *G°=-RT lnK*, but I don't get the right answer with this formula. Could someone ... |
How can I calculate the equilibrium constant for this reaction? |
Which of $\ce{S^2-}$ and $\ce{S}$ has smaller ionization energy?
On one hand, ionization energy of $\ce{S^2-}$ can be predicted to be smaller than that of $\ce{S}$ because it is "easier" to remove and electron from an electron-rich ion, which already experiences a lot of electron-electron repulsion and reduced $\ce{... |
> Silver(II) oxide partially decomposes into solid silver and oxygen gas according to:
> $$\ce{2 AgO(s) <=> 4 Ag(s) + O2(g)}$$
> with enthalpy $H^\circ = \pu{62.0 kJ}$ and entropy $S^\circ = \pu{133.6 J K-1}.$
> **a**) Calculate the change in standard Gibbs free energy. (Answer: $\pu{22.2 kJ}$)
> **b**) Cal... |
Is Phosphate (PO4 3-) solube in water? |
What is the limitations of the Hendersson-Hasselbalch Equation? |
I have been trying to balance this chemical reaction in an "acidic" medium without using oxidation number or ion electron method: [$\ce{Fe^2+ + Cr2O7^2- -> Cr^3+ + Fe^3+}$].
Though I can balance number of atoms on both the sides $[\ce{Fe^2+ + Cr2O7^2- + 14H+ -> 2 Cr^3+ + Fe^3+ + 7 H2O}]$, but charge is still unbala... |
What are the limitations of the Hendersson-Hasselbalch Equation? |
I can figure out the value of 'n' in simple equations like
Fe³⁺ + e⁻ → Fe²⁺ (which would be n=1 here.)
But in equations like 2Cu⁺→ Cu²⁺ + Cu, I can't figure it out. I assumed the value of n would be 2 here as two electrons are involved in the disproportionation reaction, but my book says n=1 here. Can anyone help ... |
How to find out the value of 'n' in the equation (ΔG = −nFE)? |
In an online test, the following question was asked:
[![enter image description here][1]][1]
The answer to this question was:
[![enter image description here][2]][2]
I totally agree with the answer, as $\ce{OCH_3}$ is an EDG, hence it will tend to form meta product in this reaction.
<hr />
While reading... |
Our instructor told us that prior to the equivalence point, the $\mathrm{pH}$ of a solution is dependent on the HH equation. However, when I tried practicing for polyprotic acid titration, I came upon this problem that does not make any sense at all. When I'm using the HH equation, the $\mathrm{pH}$ I get is lower than... |
What are the limitations of the Hendersson-Hasselbalch equation? |
Does all radiation glow green and mutates people on contact? |
What Is the Difference Between Radiation and Radioactivity? |
According to most textbook and the Wikipedia page of lanthanide contraction, the phenomenon is due to poor shielding of nuclear charge by 4f electrons. However, the σ value of 4f electrons to 6s is 1.00 in Slater’s rule, meaning that if we go through the lanthanide elements, there should be no net change in the effecti... |
Are Slater’s rule and lanthanide contraction contradictory? |
A balanced equation must have a mass balance i.e., the masses should be equal on both sides and charges must be balanced as well. Oxidation number is just a way of book-keeping. Nothing fundamental there.
$$\ce{Fe^2+ + Cr2O7 + 14H+ -> 2 Cr^3+ + Fe^3+ 7 H2O}$$
What are you forgetting? It is mass balanced. Does $\c... |
just had a conceptual question from radial wave functions.
I wanted to know if there is a possibility of an electron being *AT* the nucleus for s-orbitals, meaning that it is present at a distance of 0.00mm from the nucleus.
From the attached images, it is clear that the function is at zero for p and d orbitals,... |
Probability of finding an electron "AT" the nucleus? |
Just had a conceptual question from radial wave functions.
I wanted to know if probability density *AT* the nucleus is maximum, or zero.
From the attached images, it is clear that the function is at zero for p and d orbitals, but TENDS to infinity as approaching r = 0 for the s-orbitals. Is the value of the func... |
Probability density "AT" the nucleus? |
>The energy of an orbital is proportional to its mean radial distance, and since the 3d orbital is much larger it is much higher in energy than the 3s and 3p orbitals
**All references from JD Lee Concise inorganic chemistry**
>However, d orbitals are in general too large and too high in energy to mix completely wit... |
Which of $\ce{S^2-}$ and $\ce{S}$ has smaller ionization energy?
On one hand, ionization energy of $\ce{S^2-}$ can be predicted to be smaller than that of $\ce{S}$ because it is "easier" to remove and electron from an electron-rich ion, which already experiences a lot of electron-electron repulsion and reduced $Z_\m... |
Title. I'm quite curious about this:
In a basis set (I'll just use minimal-basis STO-nG basis sets for convenience), the basis functions are written as a linear combination of primitive GTOs. Are the GTOs normalised first, like this:
$Ψ^{STO} = Σ N_i c_i φ_i^{GTO}$
where $φ_i^{GTO}$ are un-normalised GTO funct... |
are primitive GTOs normalised before contraction, or is the resultant basis function normalised afterwards? |
> [![azulene bromination][1]][1]
I found this question and the answer as shown in my book. I didn't understand why the bromine particularly entered the position shown in the answer.
First of all, if a free radical was generated there it would be 2°, and also will have resonance. Is any other product possible or t... |
Not just in the '20s but up to the '90s at least, the d-spacings were estimated by hand measurements of diffractometer peaks or film lines and applying the Bragg formula. d-spacings were then ranked from the most intense down to the least intense. Starting with the 2 most intense d-spacing values - and allowing +/- 0.0... |
Not just in the '20s but up to the '90s at least, the d-spacings were estimated by hand measurements of diffractometer peaks or film lines and applying the Bragg formula. d-spacings were then ranked from the most intense down to the least intense. Starting with the 2 most intense d-spacing values - and allowing +/- 0.0... |
I'm quite curious about this:
In a basis set (I'll just use minimal-basis STO-nG basis sets for convenience), the basis functions are written as a linear combination of primitive GTOs. Are the GTOs normalised first, like this:
$Ψ^{STO} = Σ N_i c_i φ_i^{GTO}$
where $φ_i^{GTO}$ are un-normalised GTO functions, a... |
With the Thermo-Fisher Fusion Orbitrap mass spectrometer I can do both CID (collision-induced dissociation) and HCD (higher energy C trap dissociation) collision-induced dissociation studies.
When I apply HCD on inorganic molecules I observe more fragmentation products than with just CID suggesting multiple fragmen... |
I live in Florida--incredibly wet environment-very difficult to get moisture out of house w/o using de-humidifier 24/7--which is too expensive. Would charcoal briquettes be of any use? |
will charcoal briquettes (not activated) absorb water out of the air in the house in a sub tropical climat? |
[This source][1] lists polypropylene as suitable for use with NaOH.
However, [this paper][2] seems to demonstrate that NaOH slowly degrades polypropylene (even at fairly moderate temperatures).
Does anyone know more about this? Would anyone know for instance what it could degrade into (potential for trace cont... |
### Brief overview of CID vs. HCD
"Collision-induced dissociation" or CID is a much older and more general term in mass spectrometry than HCD. HCD is a vendor-specific term invented to describe a new modification on how ions can be dissociated in Orbitrap mass spectrometers. CID is a "universal" term that applies ... |
[This source][1] lists polypropylene as suitable for use with NaOH.
However, [this paper][2] seems to demonstrate that NaOH slowly degrades polypropylene (even at fairly moderate temperatures).
Does anyone know more about this? Would anyone know for instance what it could degrade into (potential for trace contam... |
Can the Galvanic cell use a different ionic solution? |
The body of your question shows that your primary concern isn't charcoal's hygroscopic character per se but it's suitability as a practical means to lower the relative humidity inside your house.
Let's start with it's hygroscopic character: It seems that charcoal indeed displays hygroscopic properties (the propensit... |
Just to add a bit to Ben's excellent answer...
- A number of fluorinating agents also react with PTFE, $\ce{XeF2}$ and $\ce{CoF3}$ being examples
- Ben mentioned the reaction of magnesium metal. Typically with metals, they must be in intimate contact with the PTFE surface, so molten metals or metals dissolved in... |
[Polytetrafluoroethylene][1] was discovered by accident. It now is an important material in the industry mainly because of its extremely high bonding energy, which prevents corrosion, halts reaction, and reduces friction (yeah [carbon-fluorine bonds!][2])
And people would have definitely put it to the test, making i... |
I am considering labware options to handle NaOH solutions between 200-300C. One appealing idea would be to coat my current glassware with gold. I've read different sources mentioning the possibility without further detail.
The most detailed description of a process for this is [this pdf][1] by a manufacturer who sel... |
Gold Plating on Glass? |
Order of internal pressure resistance to expect from laboratory glassware? |
Does it sometimes take energy to create a chemical bond? |
The body of your question shows that your primary concern isn't charcoal's hygroscopic character per se but it's suitability as a practical means to lower the relative humidity inside your house.
Let's start with it's hygroscopic character: It seems that charcoal indeed displays hygroscopic properties (the propensit... |
With the Thermo-Fisher Fusion Orbitrap mass spectrometer I can do both CID (collision-induced dissociation) and HCD (higher energy C trap dissociation) collision-induced dissociation studies.
When I apply HCD on inorganic molecules I observe more fragmentation products than with just CID suggesting multiple fragmen... |
I am new to Organic Chemistry and am struggling with the following very basic question:
Given is the following reaction:
(CH3)3CCl+NH3(aq)
I am supposed to analyse the end-product. However, how do I determine whether this is Sn1 or E1? I understand NH3 is a weak nucleophile and that the carbon atom is tertiary, ... |
I am new to organic chemistry and am struggling with the following very basic question:
Given is the following reaction:
$$\ce{(CH3)3CCl + NH3(aq) →}$$
I am supposed to analyse the end-product (the temperature is not given). However, how do I determine whether this is $\mathrm{S_N1}$ or $\mathrm{E1}?$ I unders... |
I have a question from school:
> Assuming that the element Ca had not been discovered, predict using the properties of the known element surrounding Ca its own properties such as its atomic weight and density.
How do I go about this? I don't know how to predict this, it all looks like building blocks in my head. ... |
If I have a solution of salt or sugar dissolved in water, the solute will never settle out or "fall to the bottom", no matter low long I wait. Why is that?
Since salt and sugar (in their pure, solid forms) are denser than water, I would intuitively expect that gravity would eventually pull all the salt and sugar to ... |
Why doesn't the solute settle out of a solution, such as brine or sugar water? |
I am reading rules for IUPAC Nomenclature. The following statement is from my book.
> Prefixes di, tri, tetra, etc., are not considered in deciding alphabetical order for simple substituents but considered for complex substituents.
With respect to the above statement, what does a simple or a complex substituent me... |
> Silver(II) oxide partially decomposes into solid silver and oxygen gas according to:
> $$\ce{2 AgO(s) <=> 4 Ag(s) + O2(g)}$$
> with enthalpy $H^\circ = \pu{62.0 kJ}$ and entropy $S^\circ = \pu{133.6 J K-1}.$
> **a**) Calculate the change in standard Gibbs free energy. (Answer: $\pu{22.2 kJ}$)
> **b**) Cal... |
> Silver(II) oxide partially decomposes into solid silver and oxygen gas according to:
> $$\ce{2 AgO(s) <=> 4 Ag(s) + O2(g)}$$
> with enthalpy $H^\circ = \pu{62.0 kJ}$ and entropy $S^\circ = \pu{133.6 J K-1}.$
> **a**) Calculate the change in standard Gibbs free energy. (Answer: $\pu{22.2 kJ}$)
> **b**) Cal... |
**tl;dr** The main structural component of chocolate is [cocoa butter][1], which is a blend of fatty acids (primarily oleic, palmitic, and stearic acids). Cocoa butter has multiple crystal structures, and manufacturers target a specific form which melts at around 33 °C. The fact that chocolate is about 90% sugar and co... |
We are given two buffers [a) 0.1 M phosphate buffer of pH 7.7 and (b) 0.1 M phosphate buffer at pH 6.71 . If acid is to be added to the buffers, which of them, will resist the pH changes better
I used Henderson Hesselbach equation in both cases but the log part and pka is same, so how to solve it? Please pr... |
How to find the resist in pH change when both are same buffers of same concentration? |
I am new to organic chemistry and was asked to rank the following materials according to energetic stability. I think I have understood that the way to do this is to count the amount of α-hydrogens: the more α-hydrogens, the more stable the molecule. However, the definition of an α-hydrogen is "a hydrogen that is attac... |
I have some chalk and I need to turn it into CaO. Would a big bonfire be hot enough to make it? If anyone has personal experience with this reaction please share, whether succesful or not |
Could Calcium Oxide be made from CaCO3 in a bonfire? |
How is it that buffers of different compositions can have the same pH?for example it is possible to prepare 0.01M phosphate buffer of pH 7.0 and 0.1M phosphate buffer of pH 7.0 How?
I used Henderson Hesselbach equation but still failed. No way is working., Is it something related to volume? Can it be shown mathe... |
How can I prepare two phosphate buffer of different concentrations but give same pH? |
My question is why size is not taken into consideration when deciding major contributors of resonance structures, particularly: why does the formal charge is always assigned to the most electronegative atom, but not necessarily the one that can "better hold a negative charge"?
**Example**: Thiocyanate. Everywhere I'... |
Formal charge: size vs electronegativity? |
How is it that buffers of different compositions can have the same pH? For example, it is possible to prepare 0.01 M phosphate buffer of pH 7.0 and 0.1 M phosphate buffer of pH 7.0? How?
I used Henderson-Hasselbalch equation, but still failed. No way is working. Is it something related to volume? Can it be shown mat... |
we use the Henderson-Hasselbalch equation, then
pH=pKa+log[HCO3−][H2CO3]
Moreover here pka of HCO3- is given whereas the Acid Is H2CO3, and also if we consider second dissociation that is Pka2 then also it is wrong because HCO3- will diss... |
How can the pCo2 and Conc of CO2 be calculated in this problem? |
> A man suffering from untreated diabetes mellitus is admitted to a hospital. Doctors fear that his blood $\mathrm{pH}$ may have dropped because of ketoacidosis. Analysis of his blood reveals that $[\ce{HCO3-}] = \pu{16 mM}$ and $p_\ce{CO2} = 30.$ If $\mathrm{p}K_\mathrm{a}$ of $\ce{HCO3-}$ is $6.1,$ determine whether ... |
How to determine pressure and concentration of carbon dioxide in blood plasma? |
>The heat content of the products is more than that of the reactant in an ............. Reaction
In this question answer given is "exothermic" but what I thought that the answer should be endothermic the since the products have more heat content and energy cannot be created or destroyed therefore from the reactant si... |
Don't blame yourself. This is a badly-worded question. Products and reactants don't have "heat content", they have thermal energy. That's because heat is not a property of substances. Substances don't "contain heat." Instead, heat is the flow of thermal energy across a boundary, and is a property of a *process* in w... |
Don't blame yourself. This is a badly-worded question. Products and reactants don't have "heat content", they have thermal energy. I.e., heat is not a property of substances—they don't 'contain heat.' Instead, heat is a property of *processes*; specifically, it is the flow of thermal energy across a boundary. So, fo... |
My question is why size is not taken into consideration when deciding major contributors of resonance structures, particularly: why is the formal charge always assigned to the most electronegative atom, but not necessarily to the one that can "better hold a negative charge"?
**Example**: Thiocyanate. Everywhere I've... |
>The energy of an orbital is proportional to its mean radial distance, and since the 3d orbital is much larger it is much higher in energy than the 3s and 3p orbitals
**All references from JD Lee Concise inorganic chemistry**
>However, d orbitals are in general too large and too high in energy to mix complete... |
>The heat content of the products is more than that of the reactant in an ............. Reaction
In this question the answer given is "exothermic" yet I thought the answer would be endothermic as the products have more heat content and energy cannot be created nor destroyed. Therefore, from the reactants' side, mo... |
I would like to get the molecular structure as SMILES from Gaussian output files. OpenBabel seems to be the tool made for such tasks.
However, the structure is not always correct.
One example:
[![enter image description here][1]][1]
OpenBabel conversion Gaussian09 to SMILES (left):
N1(c2ccccc2)[C]2C=CC... |
I would like to get the molecular structure as SMILES from Gaussian output files. OpenBabel seems to be the tool made for such tasks.
However, the structure is not always correct.
One example:
[![enter image description here][1]][1]
OpenBabel conversion Gaussian09 to SMILES (left):
N1(c2ccccc2)[C]2C=CC... |
>The heat content of the products is more than that of the reactant in an ............. reaction.
In this question the answer given is "exothermic"; yet I thought the answer would be endothermic as the products have more heat content and energy cannot be created nor destroyed. Therefore, from the reactants' side, m... |
Considering 1,3-butadiene (below) added to bromine water (considering it as $\ce{Br2(aq)}$):
[![enter image description here][1]][1]
I've seen online that the products are 1,2-dibromobutene and 1,4
[![enter image description here][2]][2]
but what I don't understand is why wouldn't the other double bond under... |
"This was proven in 1903 by J. J. Thomson who calculated that the momentum of the electrons hitting the paddle wheel would only be sufficient to turn the wheel one revolution per minute."
This is a line from [Wikipedia page][1].
[1]: https://en.wikipedia.org/wiki/Crookes_tube#Paddlewheel
J.J Thomson measure... |
How did Thomson calculated the momentum of electron when he didn't knew the mass of electron? |
How did Thomson calculate the momentum of electron when he didn't know the mass of electron? |
Does 1,3-butadiene in bromine/water do addition twice? |
I am reading rules for IUPAC Nomenclature. The following statement is from my book.
> Prefixes di, tri, tetra, etc., are not considered in deciding alphabetical order for simple substituents but considered for complex substituents.
With respect to the above statement, what does a simple or a complex substituent me... |
What does a simple or a complex substituent mean? |
My book says that the ions which have least value of discharge potential are deposited first in the concerned electrode because the 'require' the least energy to do so.I am confused by 'require' , do ions upon discharging gain energy or lose energy , are ions in general not less stable than neutral counterparts?<br>fu... |
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