instruction stringlengths 15 21.8k |
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I have a question about 1H NMR splitting of 3-methyl-1-butanol.
[![enter image description here][1]][1]
The spectrum looks as the following.
[![enter image description here][2]][2]
[1]: https://i.stack.imgur.com/mZYMz.png
[2]: https://i.stack.imgur.com/xvteM.png
The assignment of the NMR spectrum... |
I actually have a (or many) big issue(s) with the quote:
> The central C-atom is in an sp<sup>2</sup> hybridized state, for which the carbocations have planar geometry. The p<sub>$z$</sub>-AO remains empty.
The authors here have clearly scrambled up their reasoning, making carbocations seem as something they are ... |
Gefitinib has been shown to be an effective tyrosine kinase inhibitor in a fraction (~$10$%) of non-small cell lung cancer patients.
These patients are characterized as having a mutation (usually a deletion or missense) in the _EGFR_ gene affecting the ATP-binding site.
I have two questions:
-- How does gefiti... |
I intend to do a kinetic study of simple alcohol catalytic dehydrogenation reactions in the gas phase. I want to start with simple power law kinetics using Keq to account for the reversibility of the reactions. Would the equation below, knowing the Gibbs free energy of reaction, be valid?
[![enter image description... |
Is Keq at a given T derived from ΔGr° valid for doing simple kinetic modelling? |
I intend to do a kinetic study of simple alcohol catalytic dehydrogenation reactions in the gas phase. I want to start with simple power law kinetics using $K_\mathrm{eq}$ to account for the reversibility of the reactions. Would the equation below, knowing the Gibbs free energy of reaction, be valid?
$$Δ_\mathrm{r}G... |
Is equilibrium constant at a given temperature derived from Gibbs free energy of reaction valid for doing simple kinetic modelling? |
Why is alpha-Furoic acid less acidic than acetic acid?
Alpha furoic acid's conjugate base is aromatic and hence is more stable. Then why acetic acid is more acidic than alpha furoic acid? |
We have two solutions:
- Solution 1 is $\ce{HCOOH}$, its concentration is $c_1 = \pu{10^-2 mol/l}$, its volume is $V_1 = \pu{50 ml}$, and its $\mathrm{pH}_1 = 2.9$.
- Solution 2 is $\ce{CH3COOH}$, its concentration is $c_2 = \pu{10-2 mol/l}$, its volume is $V_2 = \pu{50 ml}$, and its $\mathrm{pH}_2 = 3.4$.
How... |
α-Furoic acid's conjugate base is aromatic and hence is more stable. Then why acetic acid is more acidic than α-furoic acid? |
On a recent quiz, we were asked the following question:
> $$\ce{A(aq) + B(aq) <=> C(aq)}$$
> At $\pu{298 K}$, the equilibrium amounts of each of the component are as follows: $[\ce{A}] = \pu{0.125 M}$, $[\ce{B}] = \pu{0.400 M}$, $[\ce{C}] = \pu{1.200 M}$. At $\pu{298 K}$, the system is perturbed by increasing the c... |
How to solve for the amount the equilibrium was disturbed with an ICE table? |
What is the largest, noncrystalline, non-polymer inorganic molecule? |
When light is passed through a collidal solution, due to Tyndall scattering, the path of light appears to be a bright cone. Why does it have to form only a conical shape?
The conditions for Tyndall effect are that the diameter of dispersed particles should not be much smaller than wavelength of light used and refrac... |
Why does Tyndall scaterring produce conical shape? |
On my organic chemistry exam there was a skeletal formula that had, supposedly 1 methyl group at each end of the skeletal formula and 1 somewhere in the middle. But is it correct if you draw a formula like that and then put those methyl groups on each end? I feel like it's very misleading because I thought that those w... |
Is it correct to put a methyl group on each end of a skeletal formula? |
When light is passed through a collidal solution, due to Tyndall scattering, the path of light appears to be a bright cone. Why does it have to form only a conical shape?
The conditions for Tyndall effect are that the diameter of dispersed particles should not be much smaller than wavelength of light used and refrac... |
It is simple.
Light always travels in a straight line and if a lens is present it would diverge or converge ( in a straight line ) accordingly.
**The question is why no other shape like maybe a hemisphere or a paraboloid ?**
Now let me ask the question, have you seen such thing?
[Check out this diagram to make everyt... |
On my organic chemistry exam there was a skeletal formula that had, supposedly one methyl group at each end of the skeletal formula and one somewhere in the middle.
[![Skeletal formula from my exam question][1]][1]
But is it correct if you draw a formula like that and then put those methyl groups on each end? I f... |
It is simple.
Light always travels in a straight line and if a lens is present it would diverge or converge ( in a straight line ) accordingly.
**The question is why no other shape like maybe a hemisphere or a paraboloid ?**
Now let me ask the question, have you seen such thing?
[Check out this diagram to make everyt... |
I am making a simple restricted HF code using the Python interface of Psi4. I am now evaluating convergence by tracking the change in the sum of orbital energies, but I want to do this in a better way. It is common to use the fact that at self-consistency, the Fock and density matrices commute
$$
[\mathbf{F}, \math... |
>How would be the equation and the ICE table, and what is the pH of the mixture of these two solutions?
There are three equations:
$$\ce{HCOOH <=> H+ + HCOO-}$$
$$\ce{CH3COOH <=> H+ + CH3COO-}$$
$$\ce{H2O <=> H+ + OH-}$$
Hydroxide is a minor species, so you can neglect it. As I explain below, at the pH of th... |
I am making a simple restricted HF code using the Python interface of Psi4. I am now evaluating convergence by tracking the change in the sum of orbital energies, but I want to do this in a better way. It is common to use the fact that at self-consistency, the Fock and density matrices commute
$$
[\mathbf{F}, \math... |
>How would be the equation and the ICE table, and what is the pH of the mixture of these two solutions?
There are three equations:
$$\ce{HCOOH <=> H+ + HCOO-}$$
$$\ce{CH3COOH <=> H+ + CH3COO-}$$
$$\ce{H2O <=> H+ + OH-}$$
Hydroxide is a (very) minor species, so you can neglect it. As I explain below, at the p... |
>How would be the equation and the ICE table, and what is the pH of the mixture of these two solutions?
There are three equations:
$$\ce{HCOOH <=> H+ + HCOO-}$$
$$\ce{CH3COOH <=> H+ + CH3COO-}$$
$$\ce{H2O <=> H+ + OH-}$$
Hydroxide is a (very) minor species, so you can neglect it. As I explain below, at the p... |
I am making a simple restricted HF code using the Python interface of Psi4. I am now evaluating convergence by tracking the change in the sum of orbital energies, but I want to do this in a better way. It is common to use the fact that at self-consistency, the Fock and density matrices commute
$$
[\mathbf{F}, \math... |
I am making a simple restricted HF code using the Python interface of Psi4. I am now evaluating convergence by tracking the change in the sum of orbital energies, but I want to do this in a better way. It is common to use the fact that at self-consistency, the Fock and density matrices commute
$$
[\mathbf{F}, \math... |
I am making a simple restricted HF code using the Python interface of Psi4. I am now evaluating convergence by tracking the change in the sum of orbital energies, but I want to do this in a better way. It is common to use the fact that at self-consistency, the Fock and density matrices commute
$$
[\mathbf{F}, \math... |
Yes, HNO2 is unstable, however, [per Wikipedia](https://en.wikipedia.org/wiki/Dinitrogen_trioxide) the gaseous anhydride N2O3 is described as a:
>deep blue solid[1] is one of the simple nitrogen oxides. It forms upon mixing equal parts of nitric oxide and nitrogen dioxide and cooling the mixture below −21 °C (−6 °F)... |
Yes, HNO2 is unstable, however, [per Wikipedia](https://en.wikipedia.org/wiki/Dinitrogen_trioxide) the gaseous anhydride N2O3 is described as a:
>deep blue solid[1] is one of the simple nitrogen oxides. It forms upon mixing equal parts of nitric oxide and nitrogen dioxide and cooling the mixture below −21 °C (−6 °F)... |
I want to ask a question about the C=C streching modes of Salicylamide.
I was presented with the following spectra and asked to comment on the bonds causing the peaks.
[![enter image description here][1]][1]
I identified the molecule from this and its NMR spectra to be salicylamide.
[![Diagram of Salicylam... |
>How would be the equation and the ICE table, and what is the pH of the mixture of these two solutions?
There are three equations:
$$\ce{HCOOH <=> H+ + HCOO-}$$
$$\ce{CH3COOH <=> H+ + CH3COO-}$$
$$\ce{H2O <=> H+ + OH-}$$
Hydroxide is a (very) minor species, so you can neglect it. As I explain below, at the p... |
>How would be the equation and the ICE table, and what is the pH of the mixture of these two solutions?
There are three equations:
$$\ce{HCOOH <=> H+ + HCOO-}$$
$$\ce{CH3COOH <=> H+ + CH3COO-}$$
$$\ce{H2O <=> H+ + OH-}$$
Hydroxide is a (very) minor species, so you can neglect it. As I explain below, at the p... |
## Below a more general approach.
Suppose that we have two weak acids $\ce{HA}$ and $\ce{HB}$.
The initial concentrations are $C^0_\ce{HA}$ and $C^0_\ce{HB}$, and their constants are $K_{\mathrm{a},\ce{(HA)}}$ and $K_{\mathrm{a},\ce{(HB)}}$.
Suppose yet that volumes, $V_\ce{HA}$ and $V_\ce{HB}$, are additives.
So... |
Since -OH and —CH3 are -o,p directing groups, shouldn’t the major product be ***3-Methyl-2-nitrophenol***? Why not?[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/awAnv.jpg |
The following question comes from *General Chemistry: Principles and Modern Applications, 11th ed.* by Pettruci.
> **Example 15-33.** A mixture consisting of 0.150 mol H<sub>2</sub> and 0.150 mol I<sub>2</sub> is brought to equilibrium at 445 °C, in a 3.25 L flask. What are the equilibrium amounts of H<sub>2</sub>, ... |
Can ICE tables give two solutions? What does this mean physically? |
The following question comes from *General Chemistry: Principles and Modern Applications, 11th ed.* by Pettruci.
> **Example 15-33.** A mixture consisting of 0.150 mol H<sub>2</sub> and 0.150 mol I<sub>2</sub> is brought to equilibrium at 445 °C, in a 3.25 L flask. What are the equilibrium amounts of H<sub>2</sub>, ... |
An ICE table is moderately complicated, so it ends up seeming a bit mysterious when you get two solutions. But it's really not that mysterious at all. In fact, this sort of thing is pretty common, since it happens anytime you have two variables related to each other through a square. Let's use a very simple example ... |
When an electron is excited to a singlet state, must it flip its spin state to enter the triplet state and flip once more to the ground state? |
Compounds containing an oxime functional group, such as 2-PAM and Obidoxime, are used in the treatment of poisoning with organophosphorus compounds. These oximes reactivate the enzyme acetylcholinesterase, which has been inhibited by the OPC.
However, some organophosphorus compounds are resistant to re-activation b... |
I understand the Jablonski diagram in that it has intersystem crossing from the singlet state to the triplet state, but how many spin switches are necessary to complete to phosphores? When an electron is excited to a singlet state, must it flip its spin state to enter the triplet state and flip once more to the ground ... |
The following question comes from *General Chemistry: Principles and Modern Applications, 11th ed.* by Pettruci.
> **Example 15-33.** A mixture consisting of 0.150 mol H<sub>2</sub> and 0.150 mol I<sub>2</sub> is brought to equilibrium at 445 °C, in a 3.25 L flask. What are the equilibrium amounts of H<sub>2</sub>, ... |
Compounds containing an oxime functional group, such as 2-PAM and Obidoxime, are used in the treatment of poisoning with organophosphorus compounds. These oximes reactivate the enzyme acetylcholinesterase, which has been inhibited by the OPC.
However, some organophosphorus compounds are resistant to re-activation b... |
All organic matter seems to be inflammable when dried up. Petroleum, Alcohol, Wood, and Coal burns readily. Can I call it a general rule? Are there known exceptions? What makes them the exceptions? |
Do all anhydrous organic matter burn? |
An ICE table is moderately complicated, so it ends up seeming a bit mysterious when you get two solutions. But it's really not that mysterious at all. In fact, this sort of thing is pretty common, since it happens anytime you have two variables related to each other through a square. Let's use a very simple example ... |
I am currently studying the textbook *Mass Spectrometry*, third edition, by Jürgen H. Gross. Chapter **2.4.3 Bond Dissociation Energies and Heats of Formation** says the following:
> Great efforts have been made to generate accurate and reliable ion thermochemistry data. Once such data is available, it can be employ... |
From NCERT Class Chemistry Part 2:
> **Example 11.5**
> Write the structures of the major products expected from the following reactions:
> (a) Mononitration of 3-methylphenol
> (b) Dinitration of 3-methylphenol
> (c) Mononitration of phenyl methanoate.
> **Solution**
>The combined influence of $... |
For a substructure search I would like to search for structures containing unfused benzyl.
The idea was to explicitely add hydrogen. But apparently this does not give the expected results.
So, I assume either my understanding or expectations are wrong or I'm using RDKit not properly.
I just learnt (https://chemi... |
RDKit: how to search substructures with explicit hydrogen? |
Why does attaching an $\ce{-NO2}$ group at the *ortho* position of benzoic acid cause $\ce{-COOH}$ to become perpendicular to the plane of the benzene ring? Why doesn't the nitro group get pushed out while $\ce{-COOH}$ stays on the plane?
Also, in the case of two $\ce{-NO2}$ groups attached on the *ortho* and *meta... |
Compounds containing an oxime functional group, such as [2-PAM](https://en.wikipedia.org/wiki/Pralidoxime) and [obidoxime](https://en.wikipedia.org/wiki/Obidoxime), are used in the treatment of poisoning with organophosphorus compounds. These oximes reactivate the enzyme acetylcholinesterase, which has been inhibited b... |
Compounds containing an oxime functional group, such as [2-PAM](https://en.wikipedia.org/wiki/Pralidoxime) and [obidoxime](https://en.wikipedia.org/wiki/Obidoxime), are used in the treatment of poisoning with organophosphorus compounds. These oximes reactivate the enzyme acetylcholinesterase, which has been inhibited b... |
Why ZnS can be seen as making solution alkaline? Explain with reactions |
Why Normal modes of vibration are important when compared to translational and rotation modes. And why the frequencies for rotational and translational modes are close to zero? |
I am currently studying the textbook *Mass Spectrometry*, third edition, by Jürgen H. Gross. Chapter **2.4.3 Bond Dissociation Energies and Heats of Formation** says the following:
> **Energetics of $\ce{H}^\bullet$ loss from $\ce{CH^{+ \bullet}}$** The minimum energy needed to form a $\ce{CH_3^+}$ ion and a hydroge... |
I am currently studying the textbook *Mass Spectrometry*, third edition, by Jürgen H. Gross. Chapter **2.4.3 Bond Dissociation Energies and Heats of Formation** says the following:
> **Energetics of $\ce{H}^\bullet$ loss from $\ce{CH^{+ \bullet}}$** The minimum energy needed to form a $\ce{CH_3^+}$ ion and a hydroge... |
> $$\ce{CF_3I + NaOH(aq) -> Major Product}$$
The Major product, according to me, should be **ditrifluorometyl ether $\ce{CF3-O-CF3}$**. The hydrogen on the $\ce{-OH}$ group is very acidic and hence reacts with $\ce{CF3I}$ to give a stable compound according to the following reaction mechanism:
[![Reaction][1]][1]
... |
I came upon the following statement in a true/false question:
> Glycine can be esterified by an alcohol in the presence of inorganic acid
**Is this statement correct?**
Glycine contains the basic $\ce{-NH2}$ group, which would get protonated in the presence of inorganic acid. As a consequence, would the esterifi... |
> $$\ce{CF_3I + NaOH(aq) -> Major Product}$$
The Major product, according to me, should be **ditrifluorometyl ether $\ce{CF3-O-CF3}$**. The hydrogen on the $\ce{-OH}$ group is very acidic and hence reacts with $\ce{CF3I}$ to give a stable compound according to the following reaction mechanism:
[![Reaction][1]][1]
... |
Burning is a non-scientific term, it implies appearance of a luminous chemical reaction in a gaseous phase. It is commonly called a flame. It does not necessarily imply the presence of carbon or even oxygen. Boron and hydrogen compounds can burn in air, similarly, sodium burns in the presence of chlorine.
You can... |
> $$\ce{CF_3I + NaOH(aq) -> Major Product}$$
The Major product, according to me, should be **ditrifluoromethyl ether $\ce{CF3-O-CF3}$**. The hydrogen on the $\ce{-OH}$ group is quite acidic and hence reacts with $\ce{CF3I}$ to give a stable compound according to the following reaction mechanism:
[![Reaction][1]][1]... |
I came upon the following statement in a true/false question:
> Glycine can be esterified by an alcohol in the presence of inorganic acid
**Is this statement correct?**
Glycine contains the basic $\ce{-NH2}$ group, which would get protonated in the presence of inorganic acid. As a consequence, would the esterifi... |
**TL;DR**: It's **2** (2,2'‐dibromo‐6,6'‐diiodo‐1,1'‐biphenyl) and maybe even **3** (2,2'‐diiodo‐1,1'‐biphenyl; 2,6‐dimethyl‐1,1'‐biphenyl) at higher temperatures.
### Introduction
According to the IUPAC gold book [**chirality**](https://doi.org/10.1351/goldbook.C01058) is defined the as the geometric property of... |
In pig iron, from where does carbon in it comes from? |
How do I convert purity percentage to grams? |
**TL;DR**: It's **2** (2,2'‐dibromo‐6,6'‐diiodo‐1,1'‐biphenyl) and maybe even **3** (2,2'‐diiodo‐1,1'‐biphenyl; 2,6‐dimethyl‐1,1'‐biphenyl) at higher temperatures.
### Introduction
According to the IUPAC gold book [**chirality**](https://doi.org/10.1351/goldbook.C01058) is defined the as the geometric property of... |
Acetic Acid + K2CrO4(aq) + Ba(NO3)2 (aq) —> ? |
What are the products of these 3 reactants? Acetic Acid + K2CrO4 + Ba(NO3)2 |
What are the products of these 3 reactants? Acetic Acid + K2CrO4(aq) + Ba(NO3)2(aq) |
>There are several examples where the negative inductive effect of a substituent gets increased when a hydrogen atom on that substituent is replaced by an alkyl group.
>Some particular examples:
\begin{align}
\ce{-NR3^+} &> \ce{-NH3^+}& \ce{-OR} &> \ce{-OH}
\end{align}
About comparing $\ce{-NR3^+}$ and $\ce{-N... |
For a substructure search I would like to search for structures containing unfused benzyl.
The idea was to explicitly add hydrogen. But apparently this does not give the expected results.
So, I assume either my understanding or expectations are wrong or I'm using RDKit not properly.
I just learnt (https://chemistr... |
How to search substructures with explicit hydrogen in RDKit? |
How to perform IR spectroscopy of silica particles while inflow at different RH? |
I want to ask a question about the fragmentation of the $\ce{M_17}$ peak of Salicyclamide to a phenolic fragment.
I was reading the following paper giving a profile about [salicyclamide][1].
I want to determine a mechanism that gives the following product from the fragmentation scheme:
[![Overall fragmentati... |
In the preparation of $\ce{NH3}$ from $\ce{NH4Cl}$ and $\ce{Ba(OH)2}$, my teacher said that when heating the test tube, the test tube faces downward as opposed to upwards. Why is this so? Wouldn't the solid just fall out?
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/AvEVU.png |
Why does the test tube face downards in gas production? |
The following question comes from *General Chemistry: Principles and Modern Applications, 11th ed.* by Pettruci.
> **Exercise 15-33.** A mixture consisting of 0.150 mol H<sub>2</sub> and 0.150 mol I<sub>2</sub> is brought to equilibrium at 445 °C, in a 3.25 L flask. What are the equilibrium amounts of H<sub>2</sub>,... |
If you mean the test tube containing the solids (reaction tube), then that tube faces downwards to promote the flow of gas into the receiving tube. The idea is to let the gas sink away from the reaction zone and towards the receiving tube as it cools and becomes more dense.
The receiving tube, of course, faces down... |
I want to ask a question about the fragmentation of the $\ce{M_17}$ peak of Salicyclamide to a phenolic fragment.
I was reading the following paper giving a profile about [salicyclamide][1].
I want to determine a mechanism that gives the following product from the fragmentation scheme:
[![Overall fragmentati... |
I’m required to make a lab with this information only (particle size vs dissolving rate of a solid (molecular covalent compound-sucrose)? so far what I’m thinking is using three different kinds of sugar like table sugar,sugar cubes,and one of them grinding it but the issues is how do you find how they dissolving rate? |
I need helping making a lab out of this (particle size vs dissolving rate of a solid (molecular covalent compound-sucrose)? |
As it says: are there any reactions that require heat *and* produce heat simultaneously? |
Are there any reactions that are endothermic and exothermic? |
Is it necessary that hydrolysis of ester will only take place in excess of water? |
I've recently been taught that the 4f orbitals in lanthanides are "core-like", supposedly meaning they have radius smaller than the 4d orbitals, therefore they are not available on the outside of the atom to form covalent bonds with ligands. The lecturer then went on to say that, therefore, the bonding of lanthanides t... |
How can ionic bonding in lanthanides occur without valence orbitals available for overlap? |
An example is the accidentally formed problematic explosive nitrogen trichloride from the chlorination of a warmed ammonium salt solution, like $\ce{NH4Cl}$. To quote a source:
>Why is $\ce{NCl3}$ so unstable?
>The enthalpy of formation of $\ce{NCl3}$ is + 232 kJ mol-1, a fairly large endothermic value, a good si... |
An example is the accidentally formed problematic explosive nitrogen trichloride from the chlorination of a warmed ammonium salt solution, like $\ce{NH4Cl}$, where the reaction can rapidly transition from an endothermic to an exothermic process (albeit not precisely simultaneously). To quote a source:
>Why is $\ce{N... |
The product you are suggesting is very unstable as compared to the ones given as answers due to steric factors. Thus it would not be formed.
>Since −OH and −CH3 are o,p-directing groups, shouldn’t the major product be 3-methyl-2-nitrophenol? Why not?
The reasoning that hydroxyl and methyl are o,p directing grou... |
A possible example (reflective of a class of compounds, energetics) is the accidentally formed problematic explosive nitrogen trichloride from the chlorination of a warmed ammonium salt solution, like $\ce{NH4Cl}$, where the reaction can rapidly transition from an endothermic to an exothermic process (albeit not precis... |
Is an endothermic reaction always endothermic at all conditions of pressure, temperature etc.? Similarly for exothermic... I mean is sign of ∆H always the same as sign of ∆H°?
This might seem to be a vague doubt but I just feel that there can be a reaction with trends of energies of formation of reactants and produc... |
A possible example (reflective of a class of compounds, energetics) is the accidentally formed problematic explosive nitrogen trichloride from the chlorination of a warmed ammonium salt solution, like $\ce{NH4Cl}$, where the reaction can rapidly transition from an endothermic to an exothermic process (albeit not precis... |
A possible example (reflective of a class of compounds, energetics) is the accidentally formed problematic explosive nitrogen trichloride from the chlorination of a warmed ammonium salt solution, like $\ce{NH4Cl}$, where the reaction can rapidly transition from an endothermic to an exothermic process (albeit not precis... |
> In other words, is there a scenario where I could end up with two possible [solutions]?
No, there is always a single solution. The reaction quotient Q assumes values from zero (no products) to infinity (no reactants). It varies monotonically with the extent of reaction (the x in the ICE table). So there is always ... |
>How would be the equation and the ICE table, and what is the pH of the mixture of these two solutions?
There are three equations:
$$\ce{HCOOH <=> H+ + HCOO-}$$
$$\ce{CH3COOH <=> H+ + CH3COO-}$$
$$\ce{H2O <=> H+ + OH-}$$
Hydroxide is a (very) minor species, so you can neglect it. As I explain below, at the p... |
A possible example (reflective of a class of compounds, energetics) is the accidentally formed problematic explosive nitrogen trichloride from the chlorination of a warmed ammonium salt solution, like $\ce{NH4Cl}$, where the reaction can rapidly transition from an endothermic to an exothermic process (albeit not precis... |
A possible example (which is real and reflective of a class of compounds, energetics) is the accidentally formed problematic explosive nitrogen trichloride from the chlorination of a warmed ammonium salt solution, like $\ce{NH4Cl}$, where the reaction can rapidly transition from an endothermic to an exothermic process ... |
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