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i have a chapter and in it there was the topic on Rutherford experiment..
there is written that double charged helium particles or alpha particles were thrown to a very thin gold foil and some of the alpha particles where bounced back because there were positive particles(protons) and positive and positive always re... |
help me to know the reason why does water volume decrease when salt is added? our teacher asks us in the class but I don't find any strong reason.please help me. |
Why does water volume decrease when salt is added? |
The gold foil experiment conducted by Rutherford (or more appropriately by [Geiger and Marsden][1] under Rutherford's direction) involves a stream of $\alpha$ particles (which are helium nuclei) bombarding a thin gold foil.
Why didn't some electrons go with the alpha particles because of electrostatic attraction? S... |
What you are experiencing is the phenomenon of [partial molal properties][1] - components of a mixture contribute unequally to the properties of the mixture.
Sometimes the components of a mixture do not contribute linearly to the properties of a mixture. A well-known example is the water-ethanol system, which has n... |
>But isn't hydrogen fluoride a gas at RT and a sensible pressure?
Actually, it depends on the room in question. $HF$ boils at 19.5 C, meaning one can check if it mixes well with chill water or at relatively hight pressure.
>What would happen if you just kept adding more $HF$ gas to some water?
Learn about bi... |
I have a chapter and in it there was a topic on the Rutherford experiment.
It is written that doubly charged helium particles or alpha particles were thrown towards a very thin gold foil and some of the alpha particles where bounced back because there were positive particles (protons) and positive and positive alway... |
Why weren't the electrons attracted to doubly charged Helium particles in the Rutherford experiment? |
Test for gluten? |
Regular test tube is not really a good choice for rapid cooling for two reasons:
- it is often cheap glass,
- it has a relatively thin wall, and large space for the sample inside.
This later is important, because if you want to cool down something really quick, it should be relatively small, and have good contac... |
First of all, you should indicate if you consider the fragmentation in electron ionization or in other ionization conditions. Considering it is the electron ionization conditions and that you refer to [this spectrum][1], one can postulate for a reasonable mechanism, which can be derived from what is known on the fragme... |
How do I clean a silk tie at the knot? |
My book says that in acidic water,the negative fatty acid ions become fatty acids. However, they did not include a chemical equation to demonstrate this, so I made my own: C17H35COO- (aq) + HCl (aq) --> C17H35COOH (aq) + Cl- (aq). But according to this equation, the fatty acid ion is a base, since it gets a Hydrogen at... |
What happens when c17h35coo, a soap, reacts with an acidic solution? |
I came across a radical substitution which Methane reacts with IBr to form iodomethane and hydrogen bromide and many more products. I understand the whole process but I don't quite see how the IBr molecule will break via homolytic fission instead of heterolytic. Since Bromine is more electronegative than Iodine, wouldn... |
> The electrodes have different charges. One is positive ( the cathode ) while one is negative (anode). They will attract the particles in the solution which are charged. Hydrogen to the cathode while oxygen will go to the anode.
I have been taught that water is a covalent bond. Also I have been taught that covale... |
How can water be electrolysed if it's not ionic compound? |
![Reaction with Lucas Reagent][1]
[1]: https://i.stack.imgur.com/2avTU.jpg
What would be the product(s) if this alcohol reacts with Lucas reagent?
Would Methyl shift happen ? I heard that in Groove's process, only primary and secondary alkyl chlorides are formed.
|
What is/are the product when this reacts with Lucas reagent? |
Below is replicated Question 1 from the Final Qualifying Exam of the Australian Chemistry Olympiad, 2004B, [here][1].
**Question:**
The theory of promotion-hybridization is quite successful at explaining why covalent molecules with a central atom from period 3 or higher (e.g. $\ce{SF6}$, $\ce{PF5}$, $\ce{I3}$) ar... |
I came across a radical substitution which Methane reacts with $\ce{IBr}$ to form iodomethane and hydrogen bromide and many more products. I understand the whole process but I don't quite see how the $\ce{IBr}$ molecule will break via homolytic fission instead of heterolytic. Since Bromine is more electronegative than ... |
My book says that in acidic water, the negative fatty acid ions become fatty acids. However, they did not include a chemical equation to demonstrate this, so I made my own: $$\ce{C17H35COO- (aq) + HCl (aq) -> C17H35COOH (aq) + Cl- (aq)}$$. But according to this equation, the fatty acid ion is a base, since it gets a pr... |
What happens when C17H35COO-, a soap, reacts with an acidic solution? |
I've been quite stunned during the last Winter Olympics in Sochi by the following fact.
Temperatures were quite high, sometimes 10° Celsius, and the organizers had to do something to prevent the snow from melting. I heard on the TV the commentators saying that they were discharging salt on the tracks.
However whe... |
Over the course of my studies, my lab coat has absorbed a non-negligible amount of different chemicals, some of them nasty organic polymers, some are more insoluble inorganic compounds like $\ce{Cr2O3}$.
Even after washing the lab coat some stains remain. Is there a way to get rid of those, or should I rather buy a ... |
How can I clean my lab coat? |
A lab coat will eventually get dirty, that's why it is a good idea to wear it. I had a lot of students complaining about the condition of their coat and they asked me if they could just wash it in the washing machine. My answer was always ***no***.
As far as I remember - I am a theoretician now - a labcoat costs mu... |
Use or discard. There is no "clean." DuPont Teflon Advanced or an old can of perfluoroctanesulfonate Scotchguard for the new lab coat? Classic Scotchguard,
![classic Scotchguard][1]
An eaten lab coat decorated with holes, stains, and blackened smears of stopcock grease along the sides is a badge of honor. You ... |
First of all, I am not sure I am at the right place to ask this question, if so please tell me where move it.
I have a bottle of Powerade and after probably around 20+ refills of water, the new water I put in still taste/smell a little like powerade.
How does that happen? |
Why does the water in a Powerade bottle tastes a little like Powerade after many refills? |
I have a bottle of Powerade and after probably around 20+ refills of water, the new water I put in still tastes/smells a little like Powerade.
How does that happen? |
I am an 8th grade science teacher doing a unit on density, and I want to inhale helium and sulfur hexafluoride as a fun demonstration. I am open to using any source to purchase from, and money is not an issue (but preferably as inexpensive as possible), but what concentration should I buy (what concentration is safe to... |
I'm afraid this answer doesn't address where you can get $\ce{SF6}$, as I don't know any suppliers myself (it would probably help to specify where you are, though). I just want to straighten out the safety details and make sure you (and anyone else who reads this in the future) know what you're doing. All chemistry exp... |
I'm afraid this answer doesn't address where you can get $\ce{SF6}$, as I don't know any suppliers myself (it would probably help to specify where you are, though). I just want to straighten out the safety details and make sure you (and anyone else who reads this in the future) know what you're doing. All chemistry exp... |
I'm afraid this answer doesn't address where you can get $\ce{SF6}$, as I don't know any suppliers myself (it would probably help to specify where you are, though). I just want to straighten out the safety details and make sure you (and anyone else who reads this in the future) know what you're doing. All chemistry exp... |
I'm afraid this answer doesn't address where you can get $\ce{SF6}$, as I don't know any suppliers myself (it would probably help to specify where you are, though). I just want to straighten out the safety details and make sure you (and anyone else who reads this in the future) know what you're doing. All chemistry exp... |
I already know that thymolphthalein is soluble in alcohols, very alkaline aqueous solutions, acetone, and propylene glycol methyl ether. My questions are what other solvents dissolve thymolphthalein, and what additives increase solubility (for example, specific surfactants)? |
I have question about hetero-cyclic why do we use (the most common hetero-cyclic elements) nitrogen,oxygen,sulfur as hetero compounds most of time? |
I have question about hetero-cycles: Why do we use (the most common hetero-cyclic elements) nitrogen, oxygen, sulfur as hetero compounds most of time? |
I just read about <a href="http://en.wikipedia.org/wiki/Alchemy" title="Alchemy">Alchemy</a>. And it seems to me that many of their principles are closely <a href="http://en.wikipedia.org/wiki/Alchemy#Relation_to_the_science_of_chemistry">related</a> to chemistry.
So, here is my doubt - **Why is not possible to make... |
First of all, you should indicate if you consider the fragmentation in electron ionization or in other ionization conditions. Considering it is the electron ionization conditions and that you refer to [this spectrum][1], one can postulate for a reasonable mechanism, which can be derived from what is known on the fragme... |
Lab coats, like other forms of [PPE][1], are supposed to provide a final barrier of protection, for when all other risk mitigation strategies have failed. They are not just an expensive form of fancy cooking apron. If you are getting spills on your lab coat, you should take this as an opportunity to re-examine your lab... |
Lab coats, like other forms of [PPE][1], are supposed to provide a final barrier of protection, for when all other risk mitigation strategies have failed. They are not just an expensive form of fancy cooking apron. If you are getting spills on your lab coat, you should take this as an opportunity to re-examine your lab... |
![Thymolphthaleine synthesis][1]
[1]: https://i.stack.imgur.com/C6Bn8.png
One expects [poly(ethylene oxide)-co-(polypropylene oxide)-co-poly(ethylene oxide)] triblock surfactants will micellize it (e.g., Pluronics); possibly Tergitols. It looks too bulky to fit inside even gamma-cyclodextrin.
Hang a suitabl... |
you are making it too complicated ... its really simple!
CH3-CH2-CH2-CH2-Cl + 2Na + Cl-CH2-CH2-CH2-CH3 --> CH3-CH2-CH2-CH2-CH2-CH2-CH2-CH3(N-octane) +2NaCl
You can understand wurtz's reaction much easier this way...
I hope you get it? |
In a thought experiment, a friend proposed to me a machine capable of decomposing any object (e.g., a brick) into its molecules. I'm not a chemist or physicist, but my initial reaction was that this was certainly an environmental issue if used in a larger scale.
Is that right? Or is a molecule so basic that there w... |
Would decomposing an object into molecules be an environmental problem? |
Reading Wikipedia on "Beta Decay" they list the equation of Carbon-14 decaying into N-14.
see equation https://en.wikipedia.org/wiki/Beta_decay
I presume the 14 refers to total protons and neutrons. The 6 in C, I believe means six protons. In N, I believe the 7 refers to protons. Where did the seventh proton come... |
you are making it too complicated ... its really simple: $\ce{Bu-Cl + 2Na + Cl-Bu -> Bu-Bu + 2NaCl}$ where $\ce{Bu-{}}$ is the n-butyl group and $\ce{Bu-Bu}$ is n-octane.
You can understand wurtz's reaction much easier this way...
I hope you get it? |
I have the following question:
> Which of the following would not be used to measure changes in atmospheric gases?
>
> i) Satellites
> ii) Mass Spectrometer
> iii) Digital Thermometer
> iv) Fractional Distillation
I assumed it would be fractional distillation since you cannot really measure anythin... |
Usually, a salt have a curve that explain solubility. And the graph is smooth (doesn't have any unusual shape). But, sodium sulfate have an unusual solubility:
![enter image description here][1]
[1]: https://i.stack.imgur.com/oBfxA.png
What happen when the temperature is about 30 degree? |
Why sodium sulfate have a unusual solubility? |
For many salts there are solubility curves as a function of temperature that are smooth (don't have any kinks). Sodium sulfate, however, has a kink in the solubility-T curve at 30 degrees as shown below:
![enter image description here][1]
[1]: https://i.stack.imgur.com/oBfxA.png
What happens when the tem... |
Why does sodium sulfate have an unusual solubility-temperature curve? |
Working on a practice exam. The question is
"A volume of gas contains 0.25 moles of CO2
and 0.30 moles of N2
and .15 moles of O2.
What is the partial pressure of O2
if the total pressure was 690 mm Hg and the
temperature was 25.0 C"
I know the formula is Pa=NaRT/V
So far I know that
Na = .25
R =... |
Ideal gas law? implied volume? |
Working on a practice exam. The question is
"A volume of gas contains
0.25 moles of CO2
0.30 moles of N2
0.15 moles of O2.
What is the partial pressure of O2
if the total pressure was 690 mm Hg and the
temperature was 25.0 C"
I know the formula is Pa=NaRT/V
So far I ... |
Charge and energy are always conserved. Mass is a form of energy, and what we call 'mass number' - the sum of neutrons + protons - is a close approximation to mass (because electrons are so light, having just over a two-thousandth of the mass of a proton or a neutron).
The conversion of a neutron into a proton when ... |
Working on a practice exam. The question is
"A volume of gas contains
0.25 moles of CO2
0.30 moles of N2
0.15 moles of O2.
What is the partial pressure of O2
if the total pressure was 690 mm Hg and the
temperature was 25.0 C"
I know the formula is $P_a=\dfrac{N_aRT}{V}$... |
Yes, **temperature** and **heat** do affect the **spontaneity** and the **equilibrium** of reactions. The term heat can be referred to enthalpy, which can be quite confusing in context, as I believe you are asking about raising the temperature.
Let's first take a look at the equation for the Gibb's Free Energy and ... |
So I`m doing some practice titration problems and I came across this one:
**55.0 mL** of **0.250 M** $NaOH$ is used to titrate **35.0 ml** of $H_2SO_4$.
What is the molarity of $H_2SO_4$?
I know that the equation for this reaction is:
$\ce{H2SO4 + 2NaOH <=> Na2SO4 + 2H2O}$.
I know that I have to use the $i... |
So I`m doing some practice titration problems and I came across this one:
**55.0 mL** of **0.250 M** $NaOH$ is used to titrate **35.0 ml** of $H_2SO_4$.
What is the molarity of $H_2SO_4$?
I know that the equation for this reaction is:
$\ce{H2SO4 + 2NaOH <=> Na2SO4 + 2H2O}$.
I know that I have to use the $i... |
A few drops of water can initiate a reaction between iodine and aluminium.
https://www.youtube.com/watch?v=SKSU72-1ERc
How can this happen, since iodine is only slightly soluble in water? |
How can water catalyse a reaction between iodine and aluminium? |
In a thought experiment, a friend proposed to me a machine capable of decomposing any object (e.g., a brick) into its molecules. I'm not a chemist or physicist, but my initial reaction was that this was certainly an environmental issue if used in a larger scale.
Is that right? Or is a molecule so basic that there w... |
In a thought experiment, a friend proposed to me a machine capable of decomposing any object (e.g., a brick) into its molecules. I'm not a chemist or physicist, but my initial reaction was that this was certainly an environmental issue if used in a larger scale.
Is that right? Or is a molecule so basic that there w... |
I know that fractional distillation is used to separate two liquids that are miscible in one another and have close boiling points.
However, I am really confused about vacuum distillation and steam distillation- in which cases do we these separating techniques? Can someone please give an example |
What exactly happened when I added $\ce{KOH}$ to $\ce{H2O2}$? |
In standard periodic table layout all the elements upto 56 are in order i.e are in the same layout table, but `lanthanides and actinides` are always shown separately from the layout (http://upload.wikimedia.org/wikipedia/commons/thumb/9/98/Periodic_table_%28polyatomic%29.svg/770px-Periodic_table_%28polyatomic%29.svg.pn... |
Why lanthanides and actinides are shown separate from standard periodic table layout? |
Where can I find atomic coordinates for guanosine / cytosine / thymine / adenine (either the ribonucleotide or deoxyribonucleotide bases) where the atoms are configured in the manner we would expect in the context of an idealized B-form or A-form nucleic acid duplex? I'd like to calculate the angle between various bon... |
In standard periodic table layout , all the elements upto 56 are in order i.e are in the same layout table. However, lanthanides and actinides are always shown separately from the layout like in [this][1] layout.
> What is the reason behind this structure?
> Is this standard layout or can I represent like this ... |
We have national elections coming up in two days, and like every time the election officials will mark people's thumbs with a dab of some purple solution that leaves a brown stain on the skin (and thumbnail) that takes a while to grow out. I'm pretty sure that's a potassium permanganate solution - that stuff behaves ex... |
How can I protect my skin from KMnO4? |
If it is permanganate, the brown $\ce{MnO2}$ stain will decolorize and solubilize in acidic reductant - lemon juice, perhaps boosted with a little crushed and dissolved Vitamin C. I'd go for crystal/gentian violet or Disperse Red 9 as a marker, or a reactive Cibacron or Procion dye.
Cthulhu for Fearless Leader! ... |
There is a solid substance in a rigid cylinder with a piston placed on top such that the distance between the piston and the bottom of the cylinder is essentially zero, and then the substance decomposes and forms gas that expands and pushes the piston up against a constant external pressure to a maximum point. It then ... |
If I take a compound like cyclopentadiene (C5H6) and I substitute a nitrogen for a carbon at one of the C = C bonds (making a C = N bond), how does this typically change the hydrophobicity of the compound?
This question isn't homework - the trouble is that I'm not really a chemist. My thought here is that nitrogen ... |
Cyclopentadiene / etc. hydrophobicity after nitrogen atom substitution at a double bond? |
If I take a compound like cyclopentadiene (C5H6) and I substitute a nitrogen for a carbon at one of the C = C bonds (making a C = N bond), how does this typically change the hydrophobicity of the compound?
This question isn't homework - the trouble is that I'm not really a chemist. My thought here is that nitrogen ... |
If I take a compound like cyclopentadiene (C5H6) and I substitute a nitrogen for a carbon at one of the C = C bonds (making a C = N bond), how does this typically change the hydrophobicity of the compound?
This question isn't homework - the trouble is that I'm not really a chemist. My thought here is that nitrogen ... |
If I take a compound like cyclopentadiene (C5H6) and I substitute a nitrogen for a carbon at one of the C = C bonds (making a C = N bond), how does this typically change the hydrophobicity of the compound?
This question isn't homework - the trouble is that I'm not really a chemist. My thought here is that nitrogen ... |
If I take a compound like cyclopentadiene (C5H6) and I substitute a nitrogen for a carbon at one of the C = C bonds (making a C = N bond), how does this typically change the hydrophobicity of the compound?
This question isn't homework - the trouble is that I'm not really a chemist. My thought here is that nitrogen ... |
If the frictionless massless piston is not moving, then internal and external pressures must be equal. If the piston has mass, the internal pressure must be greater when it is stationary, to support the weight. If there is static friction, all bets are off.
Suppose the piston were a right cone rather than a right ... |
The cyclic unsaturated imine (Schiff base) will be more hydrophilic for the nitrogen lone pair hydrogen bonding and being a Lewis base toward water. You do know that CpH [4 + 2} Diels-Alder reaction reversibly thermally dimerizes, right? The endo-dimer is an exo-flip then hydrogenation away from JP-10 cruise missile ... |
I have a 14 carat gold ring with diamonds. I want to weaken the metal (to get the diamonds out with out damaging them).
If I dip the ring in sulfuric acid, will I be able to dissolve the base metal in the alloy leaving the gold in place? |
If I take a compound like cyclopentadiene (C5H6) and I substitute a nitrogen for a carbon at one of the C = C bonds (making a C = N bond), how does this typically change the hydrophobicity of the compound?
The trouble is that I'm not really a chemist. My thought here is that nitrogen is more electronegative than ca... |
I would say that the question is not quite well formulated and that the answer that you quote is even further misleading in giving the proper answer.
Finding the answer
==========================
To start, let's consider fragmentation of primary alcohols, which is the question at hands here. First of all, can we... |
I would say that the question is not quite well formulated and that the answer that you quote is even further misleading in giving the proper answer.
Finding the answer
==========================
To start, let's consider fragmentation of primary alcohols, which is the question at hands here. First of all, can we... |
I would say that the question is not quite well formulated and that the answer that you quote is even further misleading in giving the proper answer.
Finding the answer
==========================
To start, let's consider fragmentation of primary alcohols, which is the question at hands here. First of all, can we... |
#Molecular level
It depends on the molecules you obtain from the decomposition if you use [Plasma gasification](http://en.wikipedia.org/wiki/Plasma_gasification) on mixed organic-inorganic materials you have syngas ($CO$, $H_2$ ... ) and vitrify matter. Watch this [video](http://www.youtube.com/watch?v=gboSDLBV1ns) m... |
When people talk about oxides like $\ce{SiO2}$ or $\ce{Al2O3}$, they use expressions like stoichiometric or under-stoichiometric. I understand that this refers to the relative composition of materials, but I don't really know what it exactly means.
Say for $\ce{SiO2}$, does under-stoichiometric mean that it isn't ex... |
I recently added a potassium hydroxide ($\ce{KOH}$) pellet to a small droplet of hydrogen peroxide (30%) ($\ce{H2O2}$). You could clearly see the potassium hydroxide dissolving in the droplet when instantaneously the solutions began to fizz strongly (boil and/or release oxygen gas, I'm not sure) and release a lot of he... |
These are the results I got for my ecperiment. I'm having trouble in identifying them.
As you should be well aware of, Lithium and Strontium both burn with crimson red when they are placed in a flame. Now, I can't decide which one it is.
Then I was told to do an experiment with the same salt where I had to add ... |
I get increasingly nervous as I get my reports from the practical oc lab course back and one of the most ofter occuring correction marks it the question wether the peak in the IR comes from an asymetric or symetric strech. I looked at about ten book and turned google upside down and still can't answer the question in e... |
I have synthesised a compound which is basically a pyridine ring connected to a tetrazole. The procedure suggested to precipitate it at pH 1 but it did not. It then suggested to extract it with ethyl acetate.
The problem is that it is not going to the organic layer but into the aqueous layer. I have tried both at p... |
I get increasingly nervous as I get my organic lab course reports. For, I often get asked whether the peak in the IR comes from an asymmetric or symmetric stretch.
I've looked at about ten books and turned google upside down. But I still can't answer the question in every case, though our molecules are quite simple... |
I get increasingly nervous as I get my organic lab course reports. For, I often get asked whether the peak in the IR comes from an asymmetric or symmetric stretch.
I've looked at about ten books and turned google upside down. But I still can't answer the question in every case, though our molecules are quite simple... |
Do you all know of any large graphs for the vibrational spectrums of HI, HBr, HF, and HCl? I need graphs that are large enough to see the spacing between the peaks in the spectra of HCl, HBr, and HI.
Alternately, if you know of any raw data sets for any of the above, that would work. Thanks in advance. |
I understand that boiling point is a colligative property for aqueous solutions, and that it empirically depends on the mole fraction of the solute, rather than the identity of the solute. I understand the van't Hoff factor / ionic strength and why it matters. I also get that an increase in entropy is the primary drivi... |
Why doesn't the boiling point of an aqueous solution depend on intermolecular attraction? |
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