instruction stringlengths 15 21.8k |
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Adding 2 moles of grignard reagent to an ester, gives out 2 alcohols. But, if 1 mole of grignard reagent is added, will the reaction exclusively produce a ketone? How to prepare a ketone in a reaction only with esters and grignard reagent as starting materials?
CH2=CH2-C(=O)OCH3 + CH3MgBr -> CH3-CH2-CH=C=O + CH3OH
... |
What caused a colour change when I mixed two different dish soaps? |
>Lead(II) sulfide dissolves in excess nitric acid according to the equation below. Calculate the volume of $\ce{NO{(g)}}$ at $\pu{27 ^\circ C}$ and $\pu{1.10 atm}$ produced from $\pu{4.7 g}$ of $\ce{PbS(s)}$.
>
>$$\ce{3PbS{(s)} + 2NO3–{(aq)} + 8H+{(aq)} -> 3Pb^2+{(aq)} + 3S{(s)} + 2NO{(g)} + 4H2O{(l)}}$$
>
>a) $\... |
Why isn't hydrogen gas an element according to the definition of an element? |
*Apparently*, the particles of your solid are either very small, or / and not crystalline. This may complicate filtration, though this is one of the reasons filter papers used in the chem labs are sold in different grades of *paper hardness*.
A practical alternative to separate such a slurry from the liquid phase w... |
The key to toxicity is concentration, which is related to how rapidly the material disperses (or concentrates) in the environment. Which is also related to water type (fresh or salt) and temperature. MSDS sheets are a bit of a joke. They are worded in a way that fends off lawyers rather than gives detailed useful toxic... |
Filtration is a mechanical operation. Thus, if you have a *solution* of $\ce{ZnCl2}$, which (assuming you use water as solvent) dissociated into ions of $\ce{Zn^{2+}}$ and $\ce{Cl^-}$, a typical filter will not retain these ions. Instead of using some vacuum (*potential* danger to evaporate some solvent, thus alterin... |
I saw this structure in some problem. What does this mean? How to express this in form of a simple structure
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/WKsMB.png |
What does this representation of organic aromatic compounds mean? |
I'm studying SPPS at the moment, and a common problem is the formation of aspartimides. I understand how they form and why are they are a problem. What I don't understand is why don't glutamic acid residues face the same problem? They have the same functional group and a 6-membered ring is probably even more favoured t... |
Please help me, a mathematician, to make sense of entropy. I know it's a topic with about a million questions already, so I understand if this gets ingnored. Yet for the life of me, I cannot make sense of the previous answers.
So apparently the definition of entropy change in a system is $\Delta S = \int_{rev} \frac... |
Main Question:
>Are all hydrolysis reactions always non redox reactions?
eg: $\ce{N2O3 + 2H2O -> 2HNO2}$
Main possible reason for above statement to be true is Oxygen and Hydrogen generally exhibits oxidation state of +2 and +1 respectively. Do anyone has any counter example still? |
Main Question:
>Are all hydrolysis reactions always non redox reactions?
eg: $\ce{N2O3 + 2H2O -> 2HNO2}$
Main possible reason for above statement to be true is Oxygen and Hydrogen generally exhibits oxidation state of -2 and +1 respectively. |
Main Question:
>Are all hydrolysis reactions always non redox reactions?
eg: $\ce{N2O3 + 2H2O -> 2HNO2}$
Main possible reason for above statement to be true is Oxygen and Hydrogen generally exhibits oxidation state of -2 and +1 respectively. So, Oxygen and hydrogen will not change oxidation states. The atoms in ... |
What is the IUPAC Name for this complex [Cr(NH3)5Cl]Cl2?NH3, I can't even find it through the internet and also employing a find in "IUPAC's Red Book". |
What is the IUPAC Name of [Cr(NH3)5Cl]Cl2.NH3? |
Main Question:
>Are all hydrolysis reactions always non redox reactions?
eg: $\ce{N2O3 + 2H2O -> 2HNO2}$
The main reason I say that this statement is correct is because oxygen and hydrogen generally show oxidation states of -2 and +1 respectively when bonded to other atoms.
This means that any change in oxid... |
Are all hydrolysis reactions non-redox reactions? |
Main Question:
>Are all hydrolysis reactions always non redox reactions?
eg: $\ce{N2O3 + 2H2O -> 2HNO2}$
The main reason I say that this statement is correct is because oxygen and hydrogen generally show oxidation states of -2 and +1 respectively when bonded to other atoms.
This means that any change in oxid... |
Are all hydrolysis reactions always non redox reactions? For example:
$$\ce{N2O3 + 2H2O -> 2HNO2}$$
The main reason I say that this statement is correct is because oxygen and hydrogen generally show oxidation states of −2 and +1 respectively when bonded to other atoms.
This means that any change in oxidation ... |
I am helping a friend with some upper-level mechanism problems. We came across this one. This is my proposal. Do you agree/disagree? Thank you for any input.
[![enter image description here][1]][1]
Source question:
[![enter image description here][3]][3]
[1]: https://i.stack.imgur.com/Aa7gT.png
[2]: htt... |
Solubility data on certain ionic compounds? |
The title may not completely explain my exact doubt so I'll explain it here:
My teacher gave me the following problem during a lecture about S<sub>N</sub>1 reactions and I had to determine the order of the rate of reaction ($k$):
[![Hydrolysis of tert-Butyl halides][1]][1]
---
As in the rate determ... |
What is the IUPAC Name for the complex $\ce{[Cr(NH3)5Cl]Cl2.NH3}$?
I can't even find it through the internet and also by employing a find in "IUPAC's Red Book". |
The title may not completely explain my exact doubt so I'll explain it here:
My teacher gave me the following problem during a lecture about S<sub>N</sub>1 reactions and I had to determine the order of the rate of reaction ($k$):
[![Hydrolysis of tert-Butyl halides][1]][1]
---
As in the rate determ... |
I have:
$$\begin{array}{c|c}
v*[S]^{-1}/\pu{s^{-1}} & \ce{v*10^2}/\pu{mol dm^-3 s^-1} \\ \hline
0.257\ & 5.15\\
0.895 & 4.48\\
2.00\ & 3.35\\
3.59\ & 1.8\\
4.82\ & 0.48\\
\hline
\end{array}$$
And I want to calculate K$_M$ graphically.
I know that I should use the equation:
$$\frac{1}{v}=\frac{1... |
[The Gold Book's definition of *adsorption*][1]
>An increase in the concentration of a dissolved substance at the interface of a condensed and a liquid phase due to the operation of surface forces. Adsorption can also occur at the interface of a condensed and a gaseous phase.
What I've learned in school is that a... |
Why is the IUPAC definition of adsorption so different from other definitions? |
[The Gold Book's definition of *adsorption*][1]
>An increase in the concentration of a dissolved substance at the interface of a condensed and a liquid phase due to the operation of surface forces. Adsorption can also occur at the interface of a condensed and a gaseous phase.
What I've learned in school is that a... |
I was reading an example in my textbook and the question goes like this:
> In a parallel radioactive decay, find energy liberated per atom of 'A' in MeV.
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/TkjUf.jpg
The solution is proceeded like this:
$$
\lambda _{1}/\lambda _{2}= \f... |
I was reading an example in my textbook and the question goes like this:
> In a parallel radioactive decay, find energy liberated per atom of 'A' in MeV.
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/TkjUf.jpg
The solution is proceeded like this:
$$
\lambda _{1}/\lambda _{2}= \f... |
I have:
$$\begin{array}{c|c}
v \cdot [S]^{-1}/\pu{s^{-1}} & \ce{v \cdot 10^2}/\pu{mol dm^-3 s^-1} \\ \hline
0.257\ & 5.15\\
0.895 & 4.48\\
2.00\ & 3.35\\
3.59\ & 1.8\\
4.82\ & 0.48\\
\hline
\end{array}$$
And I want to calculate K$_M$ graphically.
I know that I should use the equation:
$$\frac{1... |
Images are from Wikipedia.
The first obvious thing that you can see is that N2O4 is planar but N2H4 is not. And the primary reason starts here.
N2O4 can be viewed as ... |
I have:
$$\begin{array}{c|c}
v \cdot [S]^{-1}/\pu{s^{-1}} & v \cdot 10^2/\pu{mol dm^-3 s^-1} \\ \hline
0.257\ & 5.15\\
0.895 & 4.48\\
2.00\ & 3.35\\
3.59\ & 1.8\\
4.82\ & 0.48\\
\hline
\end{array}$$
And I want to calculate K$_M$ graphically.
I know that I should use the equation:
$$\frac{1}{v}=... |
I'm studying solid-phase peptide synthesis (SPPS) at the moment, and a common problem is the formation of aspartimides.
I understand how they form and why are they are a problem. What I don't understand is why don't glutamic acid residues face the same problem? They have the same functional group, and a 6-membered ... |
In solid-phase peptide synthesis, why are aspartimides a problem but not "glutamides"? |
I have:
$$\begin{array}{c|c}
\dfrac{v }{ [S]}/\pu{s^{-1}} & v \cdot 10^2/\pu{mol dm^-3 s^-1} \\ \hline
0.257\ & 5.15\\
0.895 & 4.48\\
2.00\ & 3.35\\
3.59\ & 1.8\\
4.82\ & 0.48\\
\hline
\end{array}$$
And I want to calculate $K_M$ graphically.
I know that I should use the equation:
$$\frac{1}{v}=... |
I want to be able to turn a filter on and off by electrically charging the filter so that it creates a temporary bond that blocks up the filter then, by discharging the filter, releasing the temporary bonds and allowing particles through again. Is this possible? |
Can you create a temporary bond in between an atom and a filter by electrically charging the filter? |
> Is the alpha hydrogen acidic enough to react with base?
The answer is yes. As you said +I effect of the methyl group stabilizes the carbocation. It is weakly acidic but not weak enough to not be taken by any base.
> Will it proceed through aldol reaction or will Cannizzaro reaction occur?
It will proceed th... |
First of all as @chipbuster says $\ce{HF}$ in diluted solutions in water is nearly completely dissociated and therefore **shouldn't be called weak**. [Wikipedia][1] describes this nicely and cites [several][2] [sources][3] for this claim.
It was rather difficult to prove (spectroscopic methods were used), because hy... |
my qustions are related to Ph values in irrigation water in plants
I got a Ph Meter and i am measuring the **Tap water** and i get an value about 8
My qustion is why it is that high.
To get it down. I am using a Ph Regulator of phosphoric Acid.
Next question: i am now having some Tap water With Ph value a... |
I wanted to ask something more in reference to [this question](https://chemistry.stackexchange.com/questions/7683/ortho-effect-in-substituted-aromatic-acids-and-bases).
[![Structures of 2- and 3-methoxyanilines][1]][1]
Suppose instead of toluidine, **2-methoxyaniline** and **3-methoxyaniline** are present. Now, w... |
I wanted to ask something more in reference to [this question](https://chemistry.stackexchange.com/questions/7683/ortho-effect-in-substituted-aromatic-acids-and-bases).
[![Structures of 2- and 3-methoxyanilines][1]][1]
Suppose instead of toluidine, **2-methoxyaniline** and **3-methoxyaniline** are present. Now, w... |
My following questions are related to $\mathrm{pH}$ values in irrigation water in plants.
I got a $\mathrm{pH}$ Meter and I am measuring the **tap water** and I get an value about 8.
**My first question:** Why it is that high?
To get the $\mathrm{pH}$ down, I am using a $\mathrm{pH}$ Regulator of phosphoric a... |
My following questions are related to $\mathrm{pH}$ values in irrigation water in plants.
I got a $\mathrm{pH}$ Meter and I am measuring the **tap water** and I get an value about 8.
**My first question:** Why it is that high?
To get the $\mathrm{pH}$ down, I am using a $\mathrm{pH}$ Regulator of phosphoric a... |
There’s thermochromic leuco dyes which change color with the presence of heat. However, can this be used if a molecule binds to another and the signal causes a color change of textiles/fabric? |
Can color-changing leuco dyes be used when a certain molecule binds to another? |
I had this question asked in my exam, where I was supposed to find if this pair is a diastereomer:
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/Kv19I.jpg
Now, I have learnt this rule where: Making odd number of swaps in a molecule means they both are enantiomers, and making even numbe... |
This may sound trivial but I am having a hard time linking different statements of second law. What I get from second law is that heat cannot be completely converted into work and hence efficiency of heat engine is always less than one. Please explain what it has to do with entropy. Also from second law, entropy of any... |
I would like to know why do we not need to take account of Bradford agent solution in dilution calculation ?
For example, 2.5 μg/ml BSA will calculate from 0.4 μl of 1 mg/ml BSA + 159.6 μl of distill water. The additional Bradford reagent (40 μl in my experiment) does not count in the dilution calculation. This seem... |
Why neglecting Bradford Solution Volume in the assay? |
My following questions are related to $\mathrm{pH}$ values in irrigation water in plants.
I got a $\mathrm{pH}$ meter and I am measuring the **tap water** and I get an value about 8.
**My first question:** Why it is that high?
To get the $\mathrm{pH}$ down, I am using a $\mathrm{pH}$ regulator of phosphoric a... |
Why are entries missing on a solubility data chart for ionic compounds? |
The IUPAC defintion isn't more limited than the ones you've read. Instead, it is more general.
Your confusion results from not understanding what a condensed phase is. You think a condensed phase is a 'more condensed liquid', and consequently think IUPAC is referring to a surface formed between a liquid and a 'mor... |
The IUPAC defintion isn't more limited than the ones you've read. Instead, it is more general.
Your confusion results from not being familiar with the term "condensed phase". You think a condensed phase is a 'more condensed liquid', and consequently think IUPAC is referring to a surface formed between a liquid and... |
I would like to know why do we not need to take account of Bradford agent solution in dilution calculation?
For example, $\pu{2.5 \mu g mL-1}$ BSA will calculate from $\pu{0.4 \mu L}$ of $\pu{1 mg mL-1} \ \text{BSA} + \pu{159.6 \mu L}$ of distill water. The additional Bradford reagent ($\pu{40 \mu L}$ in my experime... |
I did a separation of Bromide and Iodide ions using paper chromatography technique for 0.3% solutions of Bromide and Iodide of sodium. I got the Retention factor equal to ~0.71 for Iodide and ~0.47 for Bromide.
So, I want to ask if ion size is playing any role in deciding this retention factor? Or, is there some a... |
Why is Retention factor for Iodide greater than Bromide? |
I would like to know why do we not need to take account of Bradford agent solution in dilution calculation?
For example, $\pu{2.5 \mu g mL-1}$ BSA will calculate from $\pu{0.4 \mu L}$ of $\pu{1 mg mL-1} \ \text{BSA} + \pu{159.6 \mu L}$ of distill water. The additional Bradford reagent ($\pu{40 \mu L}$ in my experime... |
The IUPAC defintion isn't more limited than the ones you've read. Instead, it is more general.
Your confusion results from not being familiar with the term "condensed phase". You think a condensed phase is a 'more condensed liquid', and consequently think IUPAC is referring to a surface formed between a liquid and... |
> Please use simple layman terms, I am simply trying to grasp the idea.
Thermodynamics is a rigorous field, which is one of the things that makes it so powerful. Explaining something in simple layman terms will make it less powerful and more mysterious. One way around this is to pick and choose some parts that are n... |
Please help me, a mathematician, to make sense of entropy. I know it's a topic with about a million questions already, so I understand if this gets ignored. Yet for the life of me, I cannot make sense of the previous answers.
So apparently the definition of entropy change in a system is $\Delta S = \int_{rev} \frac{... |
Please help me, a mathematician, to make sense of entropy. I know it's a topic with about a million questions already, so I understand if this gets ignored. Yet for the life of me, I cannot make sense of the previous answers.
So apparently the definition of entropy change in a system is $\Delta S = \int_\mathrm{rev}... |
I'm finishing my Ph.D. in Inorganic Chemistry and having a debate with my supervisor. The work in question have two organometallic compounds A and B. The structures are based on X-Ray Diffraction, so I already have a good molecular frame and just need to optimize the hydrogens. For that I'm using PBEh-3c that usually w... |
When is it OK to change the Level of Theory? |
**NB:** This question has been edited. Originally, some of the confusion was caused by me not knowing that *condensed phase* could refer to solid phases as well. This has been removed, but the confusion caused by the other elements still remains and even the first answerer to this post was unable to clear that up.
... |
I'm finishing my Ph.D. in Inorganic Chemistry and having a debate with my supervisor. The work in question have two organometallic compounds A and B. The structures are based on X-Ray Diffraction, so I already have a good molecular frame and just need to optimize the hydrogens. For that I'm using PBEh-3c that usually w... |
Why is the IUPAC definition of adsorption so different from other definitions? |
As far as I know, the absorption of $\text{SO}_2$ in water goes under physical absorption, meaning the sulfur dioxide bubbles are held in place by Van der Waals forces, in this case Keesom forces, since both water and sulfur dioxide molecules are dipoles. [This table][1] classifies the absorption of sulfur dioxide in w... |
Can physical absorption happen despite the formation of products? |
The IUPAC defintion isn't more limited than the ones you've read. Instead, it is more general.
Your confusion results from not being familiar with the term "condensed phase". You think a condensed phase is a 'more condensed liquid', and consequently think IUPAC is referring to a surface formed between a liquid and... |
The IUPAC defintion isn't more limited than the ones you've read. Instead, it is more general.
Your confusion results from not being familiar with the term "condensed phase". You think a condensed phase is a 'more condensed liquid', and consequently think IUPAC is referring to a surface formed between a liquid and... |
In quantum mechanics, in the 'particle in a box' topic, I studied that by solving the Schrödinger equation, we can actually find out what the wave function of the particle in a box looks like. Corresponding to different energy levels, the particle can have different wave functions. For e.g., in it's ground state (lowes... |
What does the wave function of an electron look like? |
Thermochromic leuco dyes change color when the temperature changes. I want to use leuco dyes to make a color-changing fabric. However, instead of using temperature to induce color changes, I want the color to change when a molecule woven into the fabric binds to another molecule, sort of like a lateral flow/pregnancy t... |
Can color-changing leuco dyes be used to indicate when a certain molecule binds to another in a textile fabric? |
The IUPAC defintion isn't more limited than the ones you've read. Instead, it is more general.
Your confusion results from not being familiar with the term "condensed phase". You think a condensed phase is a 'more condensed liquid', and consequently think IUPAC is referring to a surface formed between a liquid and... |
As far as I know, the absorption of $\text{SO}_2$ in water goes under physical absorption, meaning the sulfur dioxide bubbles are held in place by Van der Waals forces, in this case Keesom forces, since both water and sulfur dioxide molecules are dipoles. [This table][1] classifies the absorption of sulfur dioxide in w... |
In quantum mechanics, in the 'particle in a box' topic, I studied that by solving the Schrödinger equation, we can actually find out what the wave function of the particle in a box looks like. Corresponding to different energy levels, the particle can have different wave functions. For e.g., in it's ground state (lowes... |
Is there a method to determine the concentration of EGCG by titration of green tea? |
How many stereoisomers are possible for this compound ?
[![enter image description here][1]][1]
**My Approach**<br>
the 1,4 methyl groups lie in the plane, whereas 3,5 are possible chiral centers. However I it doesn't seem like enantiomers are possible due to centre of symmetry, one structure can be meso. Apart ... |
How many stereoisomers does this compound have? |
I am conducting a school-based research project into the antioxidative properties of green tea. Part of the procedure is to determine the concentration of antioxidant in green tea. This antioxidant is [EGCG][1] (a type of *catechin*).
One of the problems I am facing is that most of the procedures I find on the inter... |
How many stereoisomers are possible for this compound ?
[![enter image description here][1]][1]
**My Approach**<br>
the 1,4 methyl groups lie in the plane, whereas 3,5 are possible chiral centers. However it doesn't seem like enantiomers are possible due to centre of symmetry, one structure can be meso. Apart fr... |
> $$\ce{CH3OH(g) + NOCl(g) <=> CH3ONO(g) + HCl(g)}$$
> The volume of the container is $\pu{433 cm^3},$ $T = \pu{50 °C}.$ Methanol was added until the pressure was $\pu{50.1 mbar},$ then $\pu{0.059 g}$ of $\ce{NOCl}$ was added. At equilibrium the partial pressure of $\ce{NOCl}$ is $\pu{27.6 mbar}.$
> Calculate $K.$
... |
Since you understand how aspartimides (succinimides) form and why are they a problem in solid-phase peptide synthesis (SPPS), I'm not going to elaborate it further. Your main question is why don't glutamic acid residues face the same problem? Then, my question is who said they (glutamic acid residues) won't? Of course,... |
I'm studying solid-phase peptide synthesis (SPPS) at the moment, and a common problem is the formation of aspartimides, which disrupt the synthetic process.
I understand how they form and why are they a problem. What I don't understand is why don't glutamic acid residues face the same problem? They have the same fu... |
In solid-phase peptide synthesis, why are the formation of aspartimides a problem but not "glutamides"? |
Why does changing the temperature shift the equilibrium? |
I think the best way to think of equilibria intuitively is in terms of rates of reaction. At equilibrium, the forward and the reverse reactions are happening at the same rate.
If you increase the temperature, what happens to the rates of the forward and reverse reactions?
Using the [Arrhenius equation][1],
$$k =... |
Since you understand how aspartimides (succinimides) form and why are they a problem in solid-phase peptide synthesis (SPPS), I'm not going to elaborate it further. Your main question is why don't glutamic acid residues face the same problem? Then, my question is who said they (glutamic acid residues) won't? Of course,... |
Since you understand how aspartimides (succinimides) form and why are they a problem in solid-phase peptide synthesis (SPPS), I'm not going to elaborate it further. Your main question is why don't glutamic acid residues face the same problem? Then, my question is who said they (glutamic acid residues) won't? Of course,... |
How many stereoisomers are possible for following compound (1,3,4,6-tetramethylcyclohex-1,4-diene)?
[![1,3,4,6-tetramethylcyclohex-1,4-diene][1]][1]
**My Approach**<br>
the 1,4 methyl groups lie in the plane, whereas 3,6 are possible chiral centers. However it doesn't seem like enantiomers are possible due to ce... |
I'm finishing my Ph.D. in Inorganic Chemistry and having a debate with my supervisor. The work in question have two organometallic compounds A and B. The structures are based on X-Ray Diffraction, so I already have a good molecular frame and just need to optimize the hydrogens. For that I'm using PBEh-3c that usually w... |
Came across a few graphs that represent the mutual solubility of two compounds in a solvent, for e.g., solubility of $\ce{KCl}$, and $\ce{NaCl}$ in $\ce{H2O}$.
On these particular graphs, I can see $x$-axis as $\pu{g}/\pu{100 mL}$ of $\ce{KCl}$, on $y$-axis as $\pu{g}/\pu{100 mL}$ of $\ce{NaCl}$. And the graph has ... |
How to read mutual solubility curves of salts with a common ion? |
According to the CRC Handbook of Chemistry and Physics, melting point of CaF2 is 1418 degrees Celsius, of Al2O3 (in its corundum form) is 2053 degress Celsius, and of Na3AlF6 is 1009 degrees Celsius (lowest of the all three). Thus the cryolite should melt first.
I have read mentions of the problem you asked in the b... |
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/YRs49.jpg
For side chain oxidation of benzene, a benzylic hydrogen is required. But, for this compound the top branch connected to the benzene ring does not have a benzylic hydrogen. So, will the top branch be broken off in the process of ... |
What product will be formed from the side-chain oxidation of this compound? |
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