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What is the condensation point of water? |
In an esterification reaction between a carboxylic acid and an alcohol, a carboxylate ester and water is produced.
I found the following diagram online, and my textbook has a similar one as well
![enter image description here][1]
**Question:** In forming the water in an esterification of a carboxylic acid, why... |
I've been searching around the internet for a while and I know that Chlorine, Bromine and Iodine are used as disinfectants.
My question is, what is the property of the halogens that make them suitable for killing microbes? Is it just their toxicity? |
Why are the halogens good disinfectants? |
This is a quote from my Chemistry textbook:
> Nitric acid ionises according to the following equation:
> $$\ce{HNO3(l) + H2O(l) -> H3O+(aq) + NO3- (aq)}$$
I know that Nitric acid formula is $\ce{HNO3}$. But I cannot understand what is the product of this equation. What is $\ce{H3O+ + NO3-}$? Is it a diluted acid w... |
Whic one is Nitric Acid, HNO3 by itself or when it is included in H2O? |
The halogens, particularly in their diatomic free states and within various oxoacids, are strong oxidizing agents by virtue of their high electronegativities, electron affinities, and reduction potentials. The polarizability of the heavier halogens also makes them almost uniquely versatile as both good leaving groups a... |
I am planning an experiment for a chemistry class about corrosion. I am going to show how different prevention methods affects the corrosion of iron and aluminium parts using bleach as the oxidizer.
One of the methods I plan on is protecting the parts using cathodic protection, the iron nail will be protected by alu... |
Whatever it is exactly, it's most likely either an actual detergent residue used when cleaning the various contact surfaces, or some preservative or binding agent for the active element of the filter. For reverse osmosis membranes, a preservative is applied to the membrane so it doesn't degrade in storage prior to firs... |
<p>
Chemistry Stack Exchange is for scientists, academics, teachers and students of <b>chemistry</b>.
</p>
<p>Questions may be of any level, but should be of the following types:</p>
<ul>
<li>Questions asking for explanation of a chemistry concept</li>
<li>Questions relating to observed chemical phenomena</li>
<... |
The most likely cause of a "soapy" taste and sudsing is a reverse osmosis filter, for which the usual [membrane preservative][1] used to keep the filter from degrading before its first use is plain old glycerin, the active ingredient of traditional soap (though most "soaps" nowadays are technically anionic surfactant "... |
The most likely cause of a "soapy" taste and sudsing from filtered water is a reverse osmosis filter, for which the usual [membrane preservative][1] used to keep the filter from degrading before its first use is plain old glycerin, the active ingredient of traditional soap (though most "soaps" nowadays are technically ... |
In an esterification reaction between a carboxylic acid and an alcohol, a carboxylate ester and water is produced.
I found the following diagram online, and my textbook has a similar one as well
https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcQ9mq0NHUu_AuMWy4FevPvFJ8ptXJ9SH5aGjDiZ4ItokoXSgROVVg
(Sorry, I... |
In an esterification reaction between a carboxylic acid and an alcohol, a carboxylate ester and water is produced.
I found the following diagram online, and my textbook has a similar one as well
![enter image description here][1]
**Question:** In forming the water in an esterification of a carboxylic acid, why... |
This question is meant for a simple (not stabilized) Ylide.
Consider the classical mechanism for the Wittig reaction given on Wikipedia:
http://en.wikipedia.org/wiki/Wittig_reaction
I am not able to understand why only one intermediate has been considered after the first step (3) instead of 4 chirally distinct i... |
Why is the Wittig reaction syn stereoselective? |
This question is about delaying/postponing chemical reactions in general, but I will explain my point based on an example. Most of you will know the famous vinegar and baking soda experiment which allows you to make a volcano or a [rocket][1]. What I have noticed when doing this experiment (in particular the rocket exp... |
This question is meant for a simple (not stabilized) Ylide.
Consider [the classical mechanism][1] for the Wittig reaction given on Wikipedia
![enter image description here][2]
I am not able to understand why only one intermediate has been considered after the first step (3) instead of 4 chirally distinct inter... |
I'm currently working with the band structure of graphene and graphene-like compounds.
α-[Boron Nitride][1] (hexagonal, single layer) has many interesting properties. I was wondering if the next period analogue, a hexagonal single-layered Aluminium Phosphide existed. Wikipedia lists [this compoind][2], but it seems ... |
Does single-layered AlN exist? |
I'm currently working with the band structure of graphene and graphene-like compounds.
α-[Boron Nitride][1] (hexagonal, single layer) has many interesting properties. I was wondering if the next period analogue, a hexagonal single-layered Aluminium Phosphide existed. Wikipedia lists [this compound][2], but it seems ... |
Does single-layered Aluminium Phosphide exist? |
I really can't understand why is the mole is a unit of measurement and not just a constant. I mean, we use units to express things that we can measure but that are not countable, that are continuous - and not discrete. Whoever, the number of atoms (or whatever) of something is clearly countable, discrete. It is also a ... |
Why is the mole a unit of measurement? |
I would like to know if formic acid (concentrated to 85%) is stable (no chimical reaction) when frozen.
Is it a good solution to store it for many years?
Thanks |
is it possible to store formic acid longer if frozen? |
Why doesn't cyclohexene have a cis-trans isomer whereas cyclodecene has one?
Is strain a factor?? |
I would like to know if formic acid (concentrated to 85%) is stable (no chemical reaction) when frozen.
Is it a good solution to store it for many years?
|
I really can't understand why is the mole a unit of measurement and not just a constant. I mean, we use units to express things that we can measure but that are not countable, that are continuous - and not discrete. However, the number of atoms (or whatever) of something is clearly countable, discrete. It is also a hug... |
> Which ions do not react with each other in solution?
>A. $Ba^{2+},SO_4^{2-},NO_3^-$
>B. $Cu^{2+},SO_4^{2-},OH^-$
>C. $Ag^+,Cl^-,H^+$
>D. $K^+,Fe^{3+},Br^-$
I have no idea why the answer is **D**. Please help.
Thank you. |
I am getting confused about this the more problems I do on it. My understanding was that only strong acids and strong bases will react to produce water and a salt. Something like this:<br><br>
Molecular Eq: $HCl(aq) + NaOH(aq) \rightarrow H_2O(l) + NaCl$<br>
Net Ionic Eq: $H^+(aq) +OH^-(aq) \rightarrow H_2O(l)$
Ma... |
I used to live near a volcano where the ground water contains naturally occurring arsenic compound. Since $As_20_3$, $As_2S_3$, and $AS_4S_4$ are predominantly occurring in drinking water, what are the processes for removing them? |
The US Environmental Protection Agency (EPA) has a page dedicated to arsenic in drinking water. [It contains a section that suggests ways to remove it from water][1].
[1]: http://water.epa.gov/drink/contaminants/basicinformation/arsenic.cfm#How%20will%20arsenic%20be%20removed%20from%20my%20drinking%20water? |
The US Environmental Protection Agency (EPA) has a page dedicated to arsenic in drinking water. [It contains a section that suggests ways to remove it from water][1].
Disclaimer: I have no idea if the arsenic removal methods on the linked page actually work. You should consult someone trained in the science of wa... |
Imagine I'm performing a primary amine to primary amine (i.e. PA to PA) crosslinking reaction at $37C$ in phosphate-buffered saline (pH $\approx 7.4$) with glutaraldehyde drawn from a $4 \%$ stock solution stored at $\approx 4C$. I've heard that glutaraldehyde, like other aldehydes, can self-polymerize under certain c... |
What is the average chain length of a glutaraldehyde crosslink between primary amines? |
Imagine I'm performing a primary amine to primary amine (i.e. PA to PA) crosslinking reaction at $37C$ in phosphate-buffered saline (pH $\approx 7.4$) with glutaraldehyde drawn from a $4 \%$ stock solution stored at $\approx 4C$. I've heard that glutaraldehyde, like other aldehydes, can self-polymerize via aldol conde... |
In [this paper][1] on page 1985 they say:
''Fluorescence analysis confirmed that enhanced protein binding
at higher electron dose depends only to a small extent on the
slight increase in the lateral dimensions of the nanodeposits but
to a much larger degree on their height (Figure 4E).''
and:
''4(E) The a... |
To my knowledge the mechanism of the Wittig reaction isn't fully resolved yet. But maybe I can give you some ideas about why the Wittig reaction with **unstabilized** ylides is Z-selective (well, with the exception of the [Schlosser modification][1]) instead of E-selective.
In the excellent book by [Clayden, Warren,... |
For a titration, if you want to know the concentration of an acid you use a strong base such as NaOh. My question is; why you can't use a weak base for this purpose? Is it because the calculation would be tougher? Is it because you'd need more of the base? I'm lost. |
In [this paper][1] on page 1985 they say:
>Fluorescence analysis confirmed that enhanced protein binding
at higher electron dose depends only to a small extent on the
slight increase in the lateral dimensions of the nanodeposits but
to a much larger degree on their height (Figure 4E).
and:
>4(E) The amo... |
For a titration, if you want to know the concentration of an acid you use a strong base such as NaOH. My question is; why you can't use a weak base for this purpose? Is it because the calculation would be tougher? Is it because you'd need more of the base? I'm lost. |
If you look online you can find various graphs of the absorption spectrum of water. The graph below for examples comes from [this blog post][1].
![absorption spectrum of light][2]
As far as I can tell these graphs come from empirical measurements. Is there a theoretical model that can derive the same or similar... |
How do you calculate the absorption spectrum of water? |
I would like to measure the ph value in dough with a ph-Meter, to ensure a ph value of 4.1 (max). Because of the high viscosity I would thin down the dough with demineralized water for two reasons:
1. I expect more accurate measurements
2. This reduces pollution of the measurement device.
As far as I understand ... |
How to measure ph-Value correctly in fluids of high viscosity (dough)? |
Chemical Equilibrium - Why does changing the temperature shift the equilibrium? |
I would like to measure the pH value of dough with a pH-Meter, to ensure a pH value of 4.1 (max). Because of the high viscosity I would thin down the dough with demineralized water for two reasons:
1. I expect more accurate measurements
2. This reduces pollution of the measurement device.
As far as I understand ... |
How can I measure the pH of high-viscosity fluids like dough? |
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]: ![equa... |
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]: ![equa... |
Chemical Equilibrium - Why does changing the temperature shift the equilibrium? |
To get the oxidation number of the carbon in the $\mathrm{C_8H_{18}}$ I should do:
$$
-\frac{18}{8}=-2.25
$$
right? But in that way, I get an oxidation number with a comma, is that normal? |
Oxidation number with comma, is it possible? |
Are fractional oxidation states possible? |
I would like to measure the pH value of dough with a pH-Meter, to ensure a pH value of 4.1 (max). Because of the high viscosity I would thin down the dough with demineralized water for two reasons:
1. I expect more accurate measurements
2. This reduces pollution of the measurement device.
As far as I understand ... |
Why is Tantalum so unreactive? |
What does $\mathrm{A}_r(\mathrm{H})$ represent when calculating the average natural weight of an elemental atom? |
To my knowledge the mechanism of the Wittig reaction isn't fully resolved yet. But maybe I can give you some ideas about why the Wittig reaction with **unstabilized** ylides is Z-selective (well, with the exception of the [Schlosser modification][1]) instead of E-selective.
In the excellent book by [Clayden, Warren,... |
To my knowledge the mechanism of the Wittig reaction isn't fully resolved yet. But maybe I can give you some ideas about why the Wittig reaction with **unstabilized** ylides is Z-selective (well, with the exception of the [Schlosser modification][1]) instead of E-selective.
In the excellent book by [Clayden, Warren,... |
To my knowledge the mechanism of the Wittig reaction isn't fully resolved yet. But maybe I can give you some ideas about why the Wittig reaction with **unstabilized** ylides is Z-selective (well, with the exception of the [Schlosser modification][1]) instead of E-selective.
In the excellent book by [Clayden, Warren,... |
Molecular imaging, using STM and AFM technologies, appear so far to visually prove most of what we already know about chemical structures, such as VSEPR theory. For instance, here are the ideal structures and AFM of a couple of cyclization reactions:
![enter image description here][1]
The question is, have there ... |
Molecular Imaging - Any surprises to be had? |
Having problems running DFTB on Gauss 09 (G09)? |
Molecular imaging, using STM and AFM technologies, appear so far to visually prove most of what we already know about chemical structures, such as VSEPR theory. For instance, here are the ideal structures and AFM of a couple of cyclization reactions:
![enter image description here][1]
We've also taken single-atom... |
My son is doing a 5th grade science fair project using ice cubes and salt water. We hypothesized that ice cubes would melt faster in salinated water but they melt slower. Is that because the salt lowers the temp of the water thereby making the water colder so the ice takes longer to melt? |
What is the effect of adding salt to ice? |
What will happen to the melting point temperature of ice if some common salt is added to it? How to justfy the answer? |
The most likely cause of a "soapy" taste and sudsing from filtered water is a reverse osmosis filter, for which the usual [membrane preservative][1] used to keep the filter from degrading before its first use is plain old glycerin, the active ingredient of traditional soap (though most "soaps" nowadays are technically ... |
I don't understand how melting point = freezing point.
For example, if liquid water freezes at 0*C how can ice also melt at 0*C? |
How can melting point equal freezing point? |
So this experiment goes like this :
1. You take an ice-cube
2. You put a thread on top face of it
3. You sprinkle some common salt on the ice-cube wherever its touching the thread
4. You wait for sometime (approx 1 min)
5. Voila! now you can lift the thread and ice-cube will stick to the end of the thread s... |
How do you explain the thread sticking to an ice-cube when salt is sprinkled over it? |
There are alkalinizing water ionizers on the market that lower the ORP of water. Does heating or cooling that water have an impact on its ORP? |
What impact does heating or cooling have on the oxidation reduction potential of water? |
I read somewhere that a silane group will react with hydroxyl groups. Does anyone know why this would happen? Thanks. |
Why does a silane group react with hydroxyl groups? |
Having problems running DFTB using dftb.org parameter files on Gauss 09 (G09)? |
I read somewhere that a silane group will react with hydroxyl groups.
Does anyone know why this would happen? |
This is balanced equation of fermentation of glucose:
$$\ce{C6H12O6(aq) -> 2C2H5OH(aq) + 2CO2(g)}$$
I know that the result of glucose fermentation is ethanol ($\ce{C2H6O}$). What represented in aforementioned equation is slightly different. I would like to know what $\ce{C2H5OH}$ is?
What is OH functional gro... |
Fermentation of glucose yielf ethanol? |
Methyl orange, bromothymol blue and phenolphthalein indicators were mix
ed together to form a solution.
![enter image description here][1]
Over what pH range would the solution be yellow?
I cannot understand the question. If two or more different indicators mixed, **DO they still work as indicators?** Becau... |
How indicators work when they mixed with each other? |
Assuming every other conditions are the same, what would be the comparison of energy required to break single bond, double bond and triple bond of a carbon atom in an organic molecule? |
As the title says, why is the melting and boiling point of ionic bond usually higher than covalent bond?
I know that compounds with ionic bonds are usually solid at room temperature, so I want other answers than this. (and this question can also be about why compounds with ionic bonds are usually solid in room temp... |
Why is the melting/boiling point of ionic bond higher than covalent bond? |
Why is this formula written with the -OH placed on the end? What is the nature of this product? |
Methyl orange, bromothymol blue and phenolphthalein indicators were mixed together to form a solution.
![enter image description here][1]
Over what pH range would the solution be yellow?
I cannot understand the question. If two or more different indicators are mixed, **do they still work as indicators?** Bec... |
How do indicators work when they mixed with each other? |
One set of comparisons is:
Why it take so much energy to turn sodium chloride molten, whereas candle wax melts virtually upon touch?
"Ionic compounds" tend to form crystals. You may have seen pictures of a crystal lattice of sodium chloride: cubic packing with a sodium being surrounded by many chlorides. It ta... |
The mixture of indicators should still work because most indicators are weak acids, and the presence of other weak acids does not interfere with any given weak acid. If you had an indicator that happened to be a weak base, you would likely have a problem, but that is not the case for your solution.
Here's a nice vi... |
We've got a mixture of carbonate salts. It's a buffer, used in fish tanks. How might we go about identifying the components and their concentrations?
I suspect it'd be hard to separate some of this guys. Yeah? |
We've got a mixture of carbonate salts. It's a buffer, used in fish tanks. How might we go about identifying the components and their concentrations?
I suspect it'd be hard to separate some of this. Is this correct? If so, why? |
A slightly deranged curiosity: if we had a 3D printer able to “print” anything starting from “cartridges” of pure chemical elements, how many of the 118+ possible cartridges (or of the 98ish for non-artificial elements) would we actually need to print most - or all - foodstuff?
(OK, one could have phrased the same q... |
How many elements in food? |
You're right--it's got to do with them being transition metals (usually). Transition metal ions form [coordination complexes][1]. Their empty $d$ orbitals accept lone pairs from other molecules (called "ligands") and form larger molecules (though we don't call them that--we call them "complexes"). When put in water, th... |
Can natural gas appliances run on Hydrogen? If so, does the appliance have to be modified and how significant of a modification would it need?
Thanks
|
Can natural gas appliances run on Hydrogen? |
As title says, why is methoxide strong base? In case of halogens, I get why one is weak base, and one is strong base, but in case of ones with oxygen, this seems to be hard to figure out. |
Why is methoxide a strong base? |
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