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We have made a crossed coil setup (X and Y transmit/receiving coils) with a SQUID pick up loop along Z.
Now we want to see EPR or NMR lines, probably using it in a CW fashion, ie. putting a ramp + lock-in oscillation in X, a CW excitation frequency in Y and demodulating the SQUID signal in Z.
Question is: **What ... |
I am studying Gaseous State.
The problem says: A mixture of gas contains N2 and C2H2.20 ml of this mixture is added to 70ml of O2 and combustion is allowed to take place over mercury. After cooling the volume of gas was found to be 68.5mL. When the resultant gas mixture is passed through a KOH solution, the volume o... |
What is the cause of decrease in volume of gaseous mixture in the following problem? |
I am currently studying gaseous state and I encountered the following problem.
>A container with a volume 3 liter holds $\ce{N2(g)}$ and $\ce{H2O(l)}$ at $\pu{29 ^\circ C}$. The pressure is found to be $\pu{1 atm}$. The water is then split into hydrogen and oxygen by electrolysis according to the reaction
$$\ce{H2... |
I am going to synthetise isopropyl salicylate. From what I have read on phillysim.org ([pdf][1]) the formation of ethyl salicylate can be catalyzed by boric acid. I could use sulfuric acid but it would be much more convenient with boric acid.
Ethanol and isopropanol have some differences, so I am not sure if it works ... |
Does anybody know if it is possible to gamma-irradiate a bottle of pH buffer to sterilise it? Are there any known effects (short-term or long-term) of the irradition process on the pH qualities of the buffer? This would be for a pH4 and pH7 buffer.
The other option I am considering is autoclaving, but I am told this... |
A volumetric flask is designed to store a relatively great volume of liquid with great accuracy. If you want to reach a determinate volume of liquid in a large backer when you add liquid to it so the liquid height increases a little bit the volume increase a lot. What you measure with your eyes for determining the volu... |
I would like to evacuate a vessel (a glass round-bottomed flask) and which contains a few grams of platinum. However, I am worried about the platinum powder being sucked up by the vacuum.
A few people told me that this is possible if I take some care, but I am still not convinced. I use a turbo pump in combination w... |
How to evacuate a glass vessel containing powders? |
[![enter image description here][1]][1]
I have been asked how I can differentiate D-glucose and D-xylose using the following reagents / reactions:
> 1. Orcinol
> 2. Benedict's test
> 3. Ammoniacal silver nitrate
> 4. $\ce{FeCl3}$
> 5. $\ce{C6H5SO2Cl}$, excess $\ce{NaOH}$
> 6. $\ce{NaOH}$, $\ce{H2O}$, heat
>... |
What reagents can be used to distinguish pentose and hexose sugars? |
I'm from a CS background and just trying to understand the real meaning behind multi phase materials. Following is the experiment which drove me towards this question.
With the help of DFT and machine learning, we identified that the material LaBiO3 could display interesting dielectric properties. Hence, a team here... |
What's the definition of multi phase materials? Does it mean the different phases represent different materials? |
I often high-vac powders on Schlenk. Issues only arise when going between positive and negative pressures though to minimise any risk I often lightly plug the sidearm of the glass stopper/adapter(?) with cotton wool. Glass wool would also suffice and I am certain there are already stoppers/adapters which have a porous ... |
I am currently studying gaseous state and I encountered the following problem.
>A container with a volume 3 liter holds $\ce{N2(g)}$ and $\ce{H2O(l)}$ at $\pu{29 ^\circ C}$. The pressure is found to be $\pu{1 atm}$. The water is then split into hydrogen and oxygen by electrolysis according to the reaction
$$\ce{H2... |
Br- and I- ions give layer test, but Cl- ion doesn't. Why? |
You run into all sorts of problems when the pH is outside of the range of 1 to 13. For example, in Environ. Sci. Technol. (2000) 342, p. 254-258, they say:
> [...] the former National Bureau of Standards (NBS) established a set of conventions that limits measurements to 1 < pH < 13 and to ionic strength, I < 0.1. Th... |
Today I came across a "thought experiment" regarding $\mathrm{pH}$ of a diluted acid solution. This idea looks somewhat logical but obviously contradicts the reality. Can you show me where is the error?
Let's suppose we have $\pu{100 g}$ of concentrated 95% (mass) sulfuric acid. That means we have a mixture of $\pu{... |
I am doing distillation using system of glassware including a flask and a glass joint. Recently I've faced a problem: the glass joint stuck in the flask. I tried to remove it but it broke and hurted my finger. I want to ask how to prevent this from happening again: can I use a scotch adhesive tape or continue using gre... |
I am doing distillation using system of glassware including a flask and a glass joint. Recently I've faced a problem: the glass joint stuck in the flask. I tried to remove it but it broke and hurted my finger. I want to ask how to prevent this from happening again: can I use a paper masking tape or continue using greas... |
Silicon grease is the one we used normally. But, your post indicates that grease hasn't worked for you. Any adhesive tape wouldn't work because it will increase the risk of leaking (specially when you are refluxing). However, we have used PTFE sleeves between joints, which have worked wonders. These sleeves are not che... |
Which metal ions precipitate in NH4OH? |
Can I get an answer stating some analogies on how electrons behave like a wave, and what does it even mean for an electron to behave like a wave?
Also, if going around the nucleus, is electron a real physical wave or a probability distribution wave? And when in motion otherwise, (like an electron shot towards somethin... |
I understand zero-filling increases the resolution of an NMR signal in the frequency domain, but I fail to comprehend how. Why do the artifical points appear between the real points in the frequency domain? Is it a byproduct of the fast fourier transform algorithm? Can someone explain this to me? Thanks! |
Electrons and photons behave similarly regarding diffraction and interference.
* First consider a *wave* going through a single slit, as the amplitude of the waveform and its diffracted component interfere, creating a high central peak and weaker side-lobes. This follows [Fraunhofer's formula][1], which applies to ... |
Imagine two pots boiling on a stove. One is tall, while one is wide. Both contain the same volume of water.
What will be the difference in the rate of evaporation between the two containers? |
When boiling water, how is evaporation rate affected by the surface area of the container? |
How can vinyl chloride arise from treating 1,2-dichloroethane with a solution of potassium hydroxide in ethanol? |
I have an anode & cathode both of 100 x 100 mm size. The process requires 450 A/m2 current density. How do I reverse calculate this? Do I use the total surface area of both Cathode and Anode or just Anode?
Please help.
Thanks |
How to calculate current density in an Electrolysis Process? |
How do I view a DSN6 file as text? |
What different areas about solvents can be explored with the conductivities collected of the alkaline hydrolysis of ethyl acetate in propanone and ethanol?
$$\ce{CH3COOC2H5 + NaOH -> CH3COONa + C2H5OH}$$
Currently, I am looking at the effect on activation energy, rates, and rate constants and the overall conversio... |
> [![What is the major product of the reaction between 4-chlorobut-1-ene?][1]][1]
When acetic acid looses hydrogen, an acetate ion is formed which attacks 4-chlorobut-1-ene, forming methyl butenoate. How does the cyclic structure form?
Does the lone pair of oxygen attack the butene moiety internally?
[1]: ... |
What is the major product of the reaction between 4-chlorobut-1-ene? |
[![What is the major product of the reaction of a geminal dibromide with silver nitrate?][2]][2]
[2]: https://i.stack.imgur.com/MVXs1.jpg
$\ce{Ag+/H2O}$ is used for peroxide formation, then followed by hydrolysis to yield an alcohol. But in the question it is a geminal dihalide and I don't know if the mechan... |
What is the major product of the reaction of a geminal dibromide with silver nitrate? |
I'm seeking to disinfect a Platypus gravity water filter made with hollow fibers. My main concern is to address any mold / mildew that may have developed inside the hollow fiber filter due to long term storage.
The manufacturer suggests
"To disinfect your Platypus filtration system, fill it with a solution of u... |
(Please excuse if this questions sounds dull; we are not professional chemists)
In our office, we discussed today what the exact definition of a salt is and whether an acid itself can be classified as a salt.
Our first problem was that we couldn't get a definitive definition for what exactly a salt is. Wikipedia ... |
Is an acid a salt? Why not? |
It is a semantics question with an open ended discussion. If you recall the old problem "How many angels can dance on a pinhead? [Medieval problem][1], this issue here is similar.
Basically in chemistry, all the terminology is controlled or endorsed by the International Union of Pure and Applied Chemistry (IUPAC). T... |
I'm using GAMESS to run a geometry optimization on a thiourea molecule, using PM6. However, the output file keeps displaying the error message, "NO FORCE FIELD, SCF DOES NOT CONVERGE." Is there an error in my input code?
$CONTRL SCFTYP=RHF RUNTYP=OPTIMIZE MAXIT=100 MULT=1 COORD=UNIQUE
NOSYM=1 $END
... |
Geometry optimization with GAMESS. Why won't SCF converge? |
It is a semantics question with an open ended discussion. If you recall the old problem "How many angels can dance on a pinhead? [Medieval problem][1], this issue here is similar.
Basically in chemistry, all the terminology is controlled or endorsed by the International Union of Pure and Applied Chemistry (IUPAC). T... |
Can I get an answer stating some analogies on how electrons behave like a wave, and what does it even mean for an electron to behave like a wave?
Also, if going around the nucleus, is electron a real physical wave or a probability distribution wave? And when in motion otherwise, (like an electron shot towards somethi... |
Is an acid a salt? Why (not)? |
Preface: Buffer solution (acid-base buffer). I am provided with a weak base, which I will designate B. $\mathrm{p}K_\mathrm{a}$ for $\ce{B}$'s conjugate acid, which I will designate $\ce{BH}$, is $8.1$, and its mole weight (sic) is $121.1$. I'm assuming the latter is the molar mass, though I don't know how that helps m... |
How to calculate the concentration of conjugate acid from given pH and pKa values? |
> A cylinder fitted with a frictionless piston is filled with $10~\mathrm{mol}$ of gaseous carbon tetrachloride and immersed in a large bath of water maintained at $300~\mathrm{K}$. The volume of the gas is initially at $V_1~\mathrm{L}$, and the external pressure on the piston is slowly decreased until the volume reach... |
> Well, i wanted to see someone doing the correct way, so i could see my mistakes and fix them
Here is the tally of bonds:
1. One H-H bond broken
2. One half O=O double bond broken
3. Two O-H bonds made
Breaking bonds costs (positive sign), making bonds gains (negative sign). The result will be an estima... |
I have been studying phase diagrams of pure substances, and for a substance such as carbon dioxide for example, it's diagram looks something like this:
[![enter image description here][1]][1]
The horizontal lines in the liquid phase puzzle me. It seems if we shrink the specific volume by a certain amount, the pre... |
What do the horizontal lines in a P-V phase diagram mean? |
> Well, i wanted to see someone doing the correct way, so i could see my mistakes and fix them
Here is the tally of bonds:
1. One H-H bond broken
2. One half O=O double bond broken
3. Two O-H bonds made
Breaking bonds costs (positive sign), making bonds gains (negative sign). The result will be an estima... |
> Well, i wanted to see someone doing the correct way, so i could see my mistakes and fix them
Here is the tally of bonds:
1. One H-H bond broken
2. One half O=O double bond broken
3. Two O-H bonds made
Breaking bonds costs (positive sign), making bonds gains (negative sign). The result will be an estima... |
I read the definition of element,
Element consists of only one kind of atom and cannot be broken down into a simpler type of matter by either physical or chemical means.
Then as per definition,
H2 is also an element as it is made of up one kind of atom but it can be broken down as in case of
H2+Cl2---- 2HCl
Here hydro... |
Here is the tally of bonds:
1. One H-H bond broken
2. One half O=O double bond broken
3. Two O-H bonds made
Breaking bonds costs (positive sign), making bonds gains (negative sign). The result will be an estimate of turning reactants to products in the gas phase. It is an estimate because the strength of a O... |
Here is the tally of bonds:
1. One $\ce{H-H}$ bond broken
2. One half $\ce{O=O}$ double bond broken
3. Two $\ce{O-H}$ bonds made
Breaking bonds costs (positive sign), making bonds gains (negative sign). The result will be an estimate of turning reactants to products in the gas phase. It is an estimate becaus... |
Karsten Theis' answer is a perfect one for your question. He also did his best to explain why is he used the bond-making bond-breaking sign conversion but you are still in mind set of product-reactant explanation. So I decided to explain it in different direction.
Remember the law of conservation of energy, which st... |
I read the definition of element:
>Element consists of only one kind of atom and cannot be broken down into a simpler type of matter by either physical or chemical means.
Then as per definition, $\ce{H2}$ is also an element as it is made of up one kind of atom but it can be broken down as in case of $\ce{H2 + Cl2... |
I am studying Gaseous State.
The problem says: A mixture of gas contains $\ce{N2}$ and $\ce{C2H2}$. $\pu{20 \\mL}$ of this mixture is added to $\pu{70\\mL}$ of $\ce{O2}$ and combustion is allowed to take place over mercury. After cooling the volume of gas was found to be $\pu{68.5\\mL}$. When the resultant gas mixtu... |
I have an anode & cathode, both of $100 \times \pu{100\\mm}$ size. The process requires $\pu{450\\A/m2}$ current density. How do I reverse calculate this? Do I use the total surface area of both Cathode and Anode or just Anode?
Please help.
Thanks |
(Please excuse if this questions sounds dull; we are not professional chemists)
In our office, we discussed today what the exact definition of a salt is and whether an acid itself can be classified as a salt.
Our first problem was that we couldn't get a definitive definition for what exactly a salt is. Wikipedia ... |
(Please excuse if this questions sounds dull; we are not professional chemists)
In our office, we discussed today what the exact definition of a salt is and whether an acid itself can be classified as a salt.
Our first problem was that we couldn't get a definitive definition for what exactly a salt is. Wikipedia ... |
In our office, we discussed today what the exact definition of a salt is and whether an acid itself can be classified as a salt.
Our first problem was that we couldn't get a definitive definition for what exactly a salt is. Wikipedia states:
> In chemistry, a salt is an ionic compound that can be formed by the ne... |
Is an acid a salt or not? |
A question I was asked was: "Why is ethanol added to chloroform bottles?". I know that chloroform can be slowly converted to poisonous phosgene gas, and that ethanol is added to prevent phosgene levels from rising. However, the options I was given were:
- It *decomposes* phosgene by converting it into ethyl carbona... |
Does ethanol "decompose" or "remove" phosgene from chloroform? |
I see two possible answers. Not (A) and (B) but rather **(A)** and **(D)**.
Chakravarthy Kalyan is responsible for reminding us that (D) can be an answer too (refer to comments).
**For option (D)**:
$\ce{HC ≡ CH + 2AgNO3 + 2NH4OH→ AgC ≡ CAg↓ + 2NH4NO3 + 2H2O}$
The greyish precipitate of [silver acetylide](h... |
I am writing a proof where I have to mention both with density and of a material and concentration of a material.
I am using the letter $\rho$ to represent density, and I didn't want to abuse the same symbol for concentration because it will make the whole proof much harder to follow. I would also prefer to avoid su... |
How to distinguish concentration and density? |
I am writing a proof where I have to mention both with density and of a material and mass concentration (mass/volume) of a material.
I am using the letter $\rho$ to represent density, and I didn't want to abuse the same symbol for concentration because it will make the whole proof much harder to follow. I would also... |
So far I know that the Hardess scale of these materials is this:
Martensite> Bainite> Perlite > Cementite> Ferrite
Where is Austenite along this scale? I know that Cementite is harder than Austenite.
|
I am writing a proof where I have to mention both with density and of a material and mass concentration (mass/volume) of a material.
I am using the letter $\rho$ to represent density, and I didn't want to abuse the same symbol for concentration because it will make the whole proof much harder to follow. I would also... |
How to distinguish mass concentration and density? |
Why Inductive Effect of NH3+ < NR3+? |
In a galvanic cell with zinc, zinc sulphate solution and copper, copper sulphate solution, if at equilibrium concentration of zinc sulphate solution increased/copper sulphate solution decreased, will current flow in the opposite direction (from copper rod to zinc rod)?
(The value of cell potential according to Nernst e... |
What sudstance emits the least light or radiation when hot with the highest vapor pressure point in a vacuum?
Ideally I would like to know in 0 gravity and 0 pressure which substance can be the hottest before the vapor pressure point is reached and/or emit the least black body radiation when hot.
https://space... |
What emits the least radiation when hot? |
> Why $\ce{-NR3+}$ has more *-I* effect than $\ce{-NH3+}?$
> And what about order of $\ce{-NHR2+}$ and $\ce{-NH2R+}?$
###My attempts
I got idea about electronegativity of carbon atom in $\ce{R}$ is more than hydrogen atom, hence positive charge gets more concentrated on nitrogen atom and it exerts more electro... |
How did Planck reach the conclusion that energy comes in packets based on black body curves? |
How can I make Phenethyl alcohol (C6H5CH2CH2) from benzene?
I have got information that Phenethyl alcohl is made from benzen by way of the Friedel-Crafts reaction between benzene and ethylene oxide in the presence of aluminium trichloride as follows.
C6H6 + CH2CH2O + AlCl3 → C6H5CH2CH2OAlCl2 + HCl
But I have n... |
How can I make phenethyl alcohol $(\ce{C6H5CH2CH2OH})$ from benzene?
I have got information that phenethyl alcohol is made from benzene by Friedel-Crafts reaction between benzene and ethylene oxide in the presence of aluminium trichloride as follows:
$$\ce{C6H6 + CH2CH2O + AlCl3 → C6H5CH2CH2OAlCl2 + HCl}$$
Bu... |
I'm building something out of weathering steel (A606). It is chemically formulated to rust until it becomes chemically stable and stops rusting. Its composition is: Carbon: 0.22%; Manganese: 1.25%; Sulphur: 0.04% and Copper: 0.2% (minimum).
I want to accelerate the "weathering" process rather than wait for Mother Na... |
I was doing an electrochemical test (LPR) and Titanium Grade 5 produced by AM respassivated oxide layer faster than produced with traditional methods. I am wondering if this can be explained with 'porosity' and being exposed to more 'surface area' as a result?
Regardless of the the porosity level, will the SLM sampl... |
Can a Titanium Grade 5 alloy produced by SLM have greater 'surface area' exposed? |
I was doing an electrochemical test (LPR) and Titanium Grade 5 produced by AM respassivated oxide layer faster than the specimen produced with traditional manufacturing under identical experimental conditions. I am wondering if this can be explained with 'porosity' and being exposed to more 'surface area' as a result?
... |
Background / theory: The electron transfer in organic materials was formalized by the Marcus theory, introducing $|H_{ab}|$ to describe the how molecules (or more generally: sites) are coupled with each other, and reorganization energy $\lambda$, about how costly it is to to accommodate a charge *after* the carrier mov... |
Can we get soap by mixing Na2CO3 from seaweeds with oil? I am not good at chemistry and saw this in an anime so i just wanted to know if it is true or not. |
Na2CO3 + oil --} soap? |
When we add magnesium to
alkyl halide, Grignard reagent is formed. $$\ce{R-X + Mg -> RMgX } $$ It is highly nucleophilic in nature. Now at this time the electrophilic alkyl halide is also present in the solution why doesn't grignard reagent simply attack the alkyl halide again ?? $$\ce{ RMgX + R-X -> R-R + MgX2}$$ W... |
Can we get soap by mixing $\ce{Na2CO3}$ from seaweeds with oil? I am not good at chemistry and saw this in an anime Dr. Stone, so I just wanted to know if it is true or not. |
I'm building something out of weathering steel (A606). It is chemically formulated to rust until it becomes chemically stable and stops rusting. Its composition is: Carbon: 0.22%; Manganese: 1.25%; Sulphur: 0.04% and Copper: 0.2% (minimum).
I want to accelerate the "weathering" process rather than wait for Mother Na... |
Background / theory: The electron transfer in organic materials was formalized by the Marcus theory, introducing $|H_{ab}|$ to describe the how molecules (or more generally: sites) are coupled with each other, and reorganization energy $\lambda$, about how costly it is to to accommodate a charge *after* the carrier mov... |
If a double bond which has two different substituents on each of it's two ends is showing resonance with one of the substituents would the double bond exhibit Geometrical isomerism?..if yes how so since the electron cloud is dispersed over them?..Moreover can the distances and relative configurations of the substituent... |
I'm trying to do a reaction with phenyl piperazine, triphosgene, and 4-bromophenol. However, every time I do this reaction I seem to get the carbonyl di-4-phenylpiperazine as a major product (based on the LCMS masses). I tried to reduce the triphosgene step to 5min, which seemed to yield trace amounts of the intended p... |
Why won't this reaction work? |
I plan to do the electrolysis of dilute sulphuric acid. This will produce hydrogen gas and oxygen gas at the anodes. I do not plan to collect these gases, but to simply let it form and release into the air without separating them. Would this carry any risk whatsoever, considering that an electric setup is nearby? |
Will mixing hydrogen and oxygen without a spark result in combustion? |
I would like to know the method of syntheses of making
1,1-Diphenyl-1-butene (C16H16) from Benzophenone ((C6H5)2CO, generally abbreviated Ph2CO) and 1-bromopropane (CH3CH2CH2Br).
I think that the carbonyl group which is a functional group composed of a carbon atom double-bonded to an oxygen atom(C=O) of Benzopheno... |
I would like to know the method of syntheses of making
1,1-diphenyl-1-butene $(\ce{C16H16})$ from benzophenone $(\ce{(C6H5)2CO},$ generally abbreviated $\ce{Ph2CO})$ and 1-bromopropane $(\ce{CH3CH2CH2Br}).$
I think that the carbonyl group which is a functional group composed of a carbon atom double-bonded to an ox... |
How to make 1,1-diphenyl-1-butene from benzophenone and 1-bromopropane? |
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