instruction stringlengths 15 21.8k |
|---|
How crystals are formed from gas? |
In crystallization, crystals are formed from liquids by cooling.
How crystals are formed from gas by cooling? |
If I have a formula containing 4 hydrogen atoms and 1 carbon
Should it be written $\small\ce{CH4}$ or $\small\ce{H4C}$?
In general, how do I know the order to put elements in, in a chemical formula?
|
Is there a way to calculate how fast water will cool if you know the water's starting temperature and temperature of the environment that you put it in, such as a freezer?
|
Is there a way to calculate how fast water will cool? |
In crystallization, crystals are formed from liquids by cooling.
How can crystals be formed from a gas by cooling? |
How are crystals formed from a gas? |
The thing I am having trouble with: why does (PCl(4)) form a +1 ion and (Cl) a -1 ion? |
How does Phosphorus Pentachloride bond? |
The thing I am having trouble with: why does $\small\ce{PCl4}$ form a +1 ion and $\small\ce{Cl}$ a -1 ion? |
Is there a way to detect bleach residue on a surface? |
If you characterize the chemical bonds to two categories physical and chemical bonds, how do you do it? Aren't all bonds ***chemical and physical***?
From the freedictionary.com, chemical bond:
> Any of several forces, especially the ionic bond, covalent bond, and metallic bond, by which atoms or ions are bound i... |
I have a solution of [copper acetate][1] and I would like to play around with the ligands to get different colors.
**Background:** The copper acetate was made through mixing vinegar (5% acetic acid), NaCl, and C$_{\textrm{(s)}}$. The deep blue-colored copper acetate spontaneously formed during a month in my dark sto... |
Are there chemical reactions that cool?
I wish to have a situation where I can mix 2 reagents at room temperature and pressure and in open air then they should react and become colder then room temperature without evaporation of some type. |
The reaction between ammonium thiocyanate and barium hydroxide octahydrate is endothermic. It absorbs heat from the surroundings.
http://www.youtube.com/watch?v=MyAzjSdc3Fc |
Are there chemical reactions that could cool down an average sized room by a noticeable amount (say 5 °C)?
I would like to investigate if it is possible to have a situation where I can mix 2 reagents at room temperature and pressure and in open air then they should react and become colder then room temperature w... |
> **Possible Duplicate:**
> [Why is methane's molecular formula conventionally “CH4”, while water is “H20” (among others)?](http://chemistry.stackexchange.com/questions/974/why-is-methanes-molecular-formula-conventionally-ch4-while-water-is-h20-a)
<!-- End of automatically inserted text... |
Here's the molecule: http://imgur.com/G4J0u
So far I've tried:
6-methylcyclohex-2-en-ol and
4-methylcyclohexen-3-ol
but both are wrong. I'm rather confused as to where I should start: the alcohol or the double bond?
Thanks! |
Naming of this molecule? |
I am new to chemistry. For some of my homework (one of many problems), I was tasked with writing a molecular equation, an overall ionic equation, and a net ionic equation for the reaction between an aqueous solution of phosphoric acid, $H_3PO_4 (aq)$ and an aqueous solution of sodium hydroxide. The products are sodiu... |
Which species disassociate completely in ionic equations? |
I am new to chemistry. For some of my homework (one of many problems), I was tasked with writing a molecular equation, an overall ionic equation, and a net ionic equation for the reaction between an aqueous solution of phosphoric acid, $H_3PO_4 (aq)$ and an aqueous solution of sodium hydroxide. The products are sodiu... |
Here's the molecule:
![enter image description here][1]
So far I've tried:
6-methylcyclohex-2-en-ol and
4-methylcyclohexen-3-ol
but both are wrong. I'm rather confused as to where I should start: the alcohol or the double bond?
[1]: https://i.stack.imgur.com/81h5h.png |
I always wanted to know what is fire made of, what can be its composition?<br/> I don't know if I'm in the correct platform to ask this but I thought it must be some chemistry related to it. Any idea is welcome. |
Composition of fire? |
I've seen it in a couple of videos, it's used to electrolyze water in 2 different containers at the same time to make a comparison and ths is very handy.
How is it called (not just hydrolizer) and where to buy it ? (couldn't find on google)
http://i1274.photobucket.com/albums/y432/mocDOTtekcubotohp/hydrolizer_zps38... |
What's the name of this electrolysis device? |
I've seen it in a couple of videos, it's used to electrolyze water in 2 different containers at the same time to make a comparison and thus is very handy.
How is it called (not just hydrolizer) and where to buy it ? (couldn't find on google)
http://i1274.photobucket.com/albums/y432/mocDOTtekcubotohp/hydrolizer_zps3... |
I've seen it in a couple of videos, it's used to electrolyze water in 2 different containers at the same time to make a comparison and thus is very handy.
What is it called (besides just a hydrolizer)?
![http://i1274.photobucket.com/albums/y432/mocDOTtekcubotohp/hydrolizer_zps38a63656.jpg][1]
[1]: https:/... |
I've been looking over the lists of materials used together to make metallic glass. Is it purely coincidental that if you round up/down any decimals from the atomic weight of elements used to construct metallic glass, you're always very close to +-1 (if not at) a prime number for the atomic weight of each element? |
I've always wondered what the chemistry behind fire is. What are the basic chemical reactions behind a simple wood fire, and how do they manifest into this phenomenon? |
What are the chemical reactions behind fire? |
Can someone explain me how can I use the periodic table in order to find the specific heat capacities of some elements? (for example, of Aluminium )
Thanks in advance ! |
I've been looking over the lists of materials used together to make metallic glass.
Is it purely coincidental that if you round up/down any decimals from the atomic weight of elements used to construct metallic glass, you're always very close to +-1 (if not at) a prime number for the atomic weight of each element? |
Can someone explain me how can I use the periodic table in order to find the specific heat capacities of some elements? (for example, of Aluminium )
|
Even though fire is one of the [Greek classical elements](http://en.wikipedia.org/wiki/Classical_element#Classical_elements_in_Greece), it is the only one that is not matter in our current understanding. What we experience as fire is the energy (in the form of light and heat) given off by the exothermic combustion of (... |
Can someone explain me how can I use the periodic table in order to find the specific heat capacities of some elements? (for example, of Aluminium )
The question I have encountered is as follows:
Given the specific heat capacities of the following liquids, use the periodic table in order to find the specific hea... |
I'm given a container of volume of 4.0 Litres that containes Nitrogen at $25 ^\circ C $ and 803 kPa.
This container is connected by a valve to another container of 10.0 litres volume that containes Aragon at $25 ^\circ C $ and $47.2 kPa $ .
We now open the valve so that the two gas are mixing .
I need to ca... |
I'm given a container of volume of 4.0 Litres that containes Nitrogen at $25 ^\circ C $ and 803 kPa.
This container is connected by a valve to another container of 10.0 litres volume that containes Aragon at $25 ^\circ C $ and $47.2 kPa $ .
We now open the valve so that the two gas are mixing .
I need to ca... |
Can someone explain me how can I use the periodic table in order to find the specific heat capacities of some elements? (for example, of Aluminium )
The question I have encountered is as follows:
> Given the specific heat capacities of the following liquids, use the periodic table in order to find the specific h... |
**Yes, it’s coincidental**. There is no expectation that prime (or near-prime) atomic weight means anything for the element itself. In fact, your affirmation is not even true: on the list given by [Wikipedia](http://en.wikipedia.org/wiki/Amorphous_metal), the first two examples are:
- $\ce{Au_75 Si_25}$, your assert... |
**Yes, it’s coincidental**. There is no expectation that prime (or near-prime) atomic weight means anything for the element itself. In fact, your affirmation is not even true: on the list given by [Wikipedia](http://en.wikipedia.org/wiki/Amorphous_metal), the first two examples are:
- $\ce{Au_75 Si_25}$, your assert... |
I am trying to build a homemade thermos. It needs to be able to conserve the heat in 125ml of water for 15 minutes.
However unlike a normal thermos, it also needs to be able to be heated. What homemade substances can I use that are not flammable, yet provide a relatively high degree of insulation?
Note my thermo... |
Homemade nonflammable thermal insulators? |
In one of the solar system documentries it was mentioned there are moons in solar system with lakes of frozen methan.
Assuming humans or robots or whatever makes it there, would there be a way to extract energy from frozen methan without oxygen? Other wise it seems the oxygen had to be carried there as well.
Is ... |
Is it possible to get energy from frozen Methan without oxygen? |
Are the half-reactions used in analyzing redox reactions a real thing or are they a conceptual shortcut?
Is there a way to, however briefly, run a half-reaction by itself without the corresponding other half? For example, reduce metal atoms to metal ions without the corresponding oxidation half-reaction?
|
Are redox half-reactions "real"? |
In one of the solar system documentaries it was mentioned there are moons in the solar system with lakes of frozen methane.
Assuming humans or robots or whatever could make it there, would there be a way to extract energy from frozen methane without using oxygen? Otherwise, it would seem that the oxygen would have t... |
Is it possible to get energy from frozen methane without oxygen? |
Hi I am reading up on entropy in a textbook and I got confused by this
It says that to calculate the entropy for this irrversible process using heat flow, one must imagine the reversible process in which the initial and final states are the same as for the irrversible process. Why is this so and why do we need to th... |
Calculating laser wavelength/power to cause emission of light in a gas? |
I would like to print some molecules rather than building them using a kit. What file formats work? |
What chemical file formats are compatible with 3D printing? |
How does the work that won the 2012 Sustainable Chemistry Award contribute to sustainable chemistry? |
Generally, all noble gases are very unreactive. Why?
I understand that it has to do with electron shielding prospective electrons that could join the atom or leave and the energies associated with both actions, but why are 5 electrons in the p orbital (to take Flourine as an example) so much worse in shielding the n... |
Why are noble gases stable? |
Generally, noble gases are very unreactive. Why?
I understand that it has to do with electron shielding prospective electrons that could join the atom or leave and the energies associated with both actions, but why are 5 electrons in the p orbital (to take Fluorine as an example) so much worse in shielding the nucle... |
I am reading up on entropy in a textbook and I got confused by this:
It says that to calculate the entropy for an irreversible process using heat flow, one must imagine the reversible process in which the initial and final states are the same as for the irrversible process. Why is this so and why do we need to think... |
How to calculate Entropy? |
I am reading up on entropy in a textbook and I got confused by this:
It says that to calculate the entropy for an irreversible process using heat flow, one must imagine the reversible process in which the initial and final states are the same as for the irreversible process. Why is this so and why do we need to thin... |
Calculating entropy: why consider a reversible path? |
I know like dissolves like, but I am still unclear. 9-flourenone is a has a polar C-O bond. Is it because 9-flournone can only form london forces with other 9-flourenone molecules and hexane can break these forces? |
The planet will have gaseous oxygen if it does have an atmosphere, and if that is the case then with enough energy(like a spark) atomized hydrocarbons could be lit for energy. What is atomizing you say? Well its just breaking a liquid apart into little particles, making it easier for the oxygen to react with said metha... |
The case of polar solvents is clear to me - we get an attraction between opposite charges. However, how do non-polar substances dissolve in non-polar solvents? How could it be explained on a molecular level? |
How do non-polar substances dissolve in non-polar solvents? |
What is the shape of the $C_2H_2$ molecule?
The fact that is has a triple covalent bond between the 2 carbon atoms and 2 other bonding pairs between the hydrogen and carbon atoms leads me to believe that it could be linear shape.
However, I'm not sure if the triple bond counts as a single electron bonding pair o... |
What immediately comes to mind is something rather obvious, don't use ammonia on any surface that could possibly be contaminated with bleach.
A search revealed a video "http://www.youtube.com/watch?v=tOhJr-iLsGo" showing red cabbage juice used as an indicator. I do not believe the limit of detection would be anythi... |
Applying pressure can result in chemical changes, does this hold true for an avocado? |
Is crushing an avocado a chemical or physical change? |
> I understand that covalent bonding is an equilibrium state between attractive and repulsive forces, but which one of fundamental forces actually causes atoms to attract each other?
**The role of Pauli Exclusion in bonding**
It is an unfortunate accident of history that because chemistry has a very convenient an... |
What immediately comes to mind is something rather obvious, don't use ammonia on any surface that could possibly be contaminated with bleach.
A search revealed a [video](http://www.youtube.com/watch?v=tOhJr-iLsGo) showing red cabbage juice used as an indicator. I do not believe the limit of detection would be anyth... |
For drawing MO diagram for heteronuclear diatomic molecule, how do I know which is lower in energy than the other?
For example, given a heteronuclear diatomic molecule NO, which one is lower in energy?
Another question is th |
For drawing MO diagram for heteronuclear diatomic molecule, how do I know which is lower in energy than the other?
For example, given a heteronuclear diatomic molecule NO, which one is lower in energy? |
I saw in a textbook that for carbonate ion, there are 3 resonance forms and the bond order is 1 and 1/3. So in general, how should we calculate the bond order for resonance structures?
Is there any definite way to do this?
Thanks in advance! |
I saw in a textbook that for carbonate ion, there are 3 resonance forms and the bond order is 1 and 1/3. So in general, how should we calculate the bond order for resonance structures?
Is there any definite way to do this? |
I know like dissolves like, but I am still unclear. 9-Fluorenone is a has a polar $\small \ce{C-O}$ bond.
Is it because 9-Fluorenone can only form London forces with other 9-Fluorenone molecules and hexane can break these forces? |
I know like dissolves like, but I am still unclear. 9-fluorenone has a polar C—O bond.
Is it because 9-fluorenone can only form London forces with other 9-fluorenone molecules and hexane can break these forces? |
Why does 9-fluorenone dissolve in hexane? |
I'd like to illustrate my question with an example:
Imagine nickel reacts with fluoride and you start with 0.766 g of nickel, an unknown amount of fluoride and you end with 1.261 g of nickelfluoride. The mass of fluoride in the end must then be 1.261 g - 0.766 g = 0.495 g. So in the end there's 0.013 moles of nickel... |
I recently learned that attempts to compare the spectra of two isomers of $C_3H_3^+$ were frustrated by the difficulty of separating the two species.
What makes these isomers difficult to separate? |
Why are isomers difficult to separate? |
I'd like to illustrate my question with an example:
Imagine nickel reacts with fluoride and you start with 0.766 g of nickel, an unknown amount of fluoride and you end with 1.261 g of nickelfluoride. The mass of fluoride in the end must then be 1.261 g - 0.766 g = 0.495 g.
So, in the end there's 0.013 moles of n... |
Your title and question are a bit different.
>Is crushing an avocado a chemical or physical change?
Physical. Crushing (or any other physical manipulation of) any substance is, by definition a physical change. However, those physical changes can affect the conditions for a chemical change, potentially causing a ... |
For example, a Phosphorus Pentachloride hybradises 5- but why not 6?
Why does water $sp^3$ hybradise even though it has enough lose pairs in its p orbital to bond with 2 Oxygen- surely it's a waste of effort to put in the energy to pull up the lower s orbital to bond when there are a surplus of ps already? |
In orbital hybradisation, how does an atom 'decide' how many orbitals it will hybradise? |
I was wondering, can I separate the $NaClO$ from the $H_2O$ in bleach. The decomposition point for $NaClO$ is $374.14K$, so I'm risking decomposing the compound if I do simple distillation. What should I do?
PS I don't have a vacuum pump.
Danke. |
Imagine two atoms, and only consider the Van der Waals force. The electron cloud will jitter- some of these jitters forming dipoles, some not. However, on average they form dipoles. Why?
Why is the potential energy of a dipole lower than a non-dipole?
How do the electrons 'decide' which ones are going to move to ... |
I was wondering, can I separate the NaClO from the H<sub>2</sub>O in bleach. The decomposition point for NaClO is 374.14 K, so I'm risking decomposing the compound if I do simple distillation. What should I do?
PS: I don't have a vacuum pump. |
For example, in Phosphorus Pentachloride 5 orbitals hybradise- but why not 6, as in the hydrated Aluminium ion (I have read that the reason 6 orbitals hybradise is that a maximum of 6 oxygens can stably fit around it- why is it not the same case for Phosphorus)?
Secondly, why does water $sp^3$ hybradise even though it... |
In orbital hybradisation, what determines the number of orbitals that hybradise to be at the same energy level? |
Imagine two atoms, and only consider the Van der Waals force. The electron cloud will jitter due to its quantum mechanical nature- some of these jitters forming dipoles, some not. However, on average they form dipoles. Why?
This question is equivalent to asking (although it is useful here to ask in another way): why ... |
I have a clogged drain from my shower. Commercial products like Savo or WC Net totally don't work. Is there any chemical substance which can be bought without permission or which can be made easily to clear the drain?
Btw, I live in Czech Republic, it's part of European Union, just for your information about the law ... |
I have a clogged drain from my shower. Commercial products like Savo or WC Net totally don't work. Is there any chemical substance which can be bought without permission or which can be made easily to clear the drain?
Btw, I live in Czech Republic, it's part of European Union, just for your information about the law ... |
I have a clogged drain from my shower. Commercial products like Savo or WC Net totally don't work. Is there any chemical substance which can be bought without permission or which can be made easily to clear the drain?
I live in Czech Republic, it's part of European Union, just for your information about the law sys... |
I have purchased an "unknown" white coloured powder from the market which can frost glass objects. Here are some properties of this powder
1) White in colour
2) When mixed with HCL or water, it results in the soluion becoming ice cold, the reaction is endothermic.
3) When kept for a while (10 minutes) the white po... |
I have purchased an "unknown" white coloured powder from the market which can frost glass objects. Here are some properties of this powder
1. White in colour
2. When mixed with HCL or water, it results in the soluion becoming ice cold, the reaction is endothermic.
3. When kept for a while (10 minutes) the white po... |
Dendrites that form on the electrodes of cells shorten the cell's lifetime, and result in reduced capacity before the end of life.
If the dendrites could be detached from the electrode, would they then dissolve back into the electrolyte, or would they remain as solids suspended in it? How does this effect battery li... |
Would the detaching of dendrites from electrodes in a cell, result in the crystal dissolving back into the electrolyte? |
''What determines which electrons are going to move to the middle of the atoms to form a dipole,...?''
Electrons are indistinguishable particles, so the question doesn't make sense. Electrons are excitations of the electron field (a quantum version of like wavelets on a lake), and their formation somewhere is just b... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.