instruction stringlengths 15 21.8k |
|---|
>Does it aid crystallization?
**Yes.**
All of the drugs that you see as "hydrochlorides" are [alkaloids][1] - a class of basic natural products containing one or more amine functional groups. The dimethylamino group in the upper right of the structure of [diphenhydramine][2] (below) is a prime example.
![enter... |
I'm a gold smith and I want to start experimenting with non-standard metal-alloys. Now high school is a long time ago for me so while I think I've got this right, I'm just not as sure as I should be when working with precious metals costing 40 dollar a gram. So could anyone confirm that what I'm doing is right:
I ha... |
>Does it aid crystallization?
**Yes.**
All of the drugs that you see as "hydrochlorides" are [alkaloids][1] - a class of basic natural products containing one or more amine functional groups. The dimethylamino group in the upper right of the structure of [diphenhydramine][2] (below) is a prime example.
![enter... |
The [Wikipedia page][1] on liquid oxygen tells us
> Liquid oxygen is also a very powerful oxidizing agent [...], if soaked in liquid oxygen, some materials such as coal briquettes, carbon black, etc., can detonate unpredictably from sources of ignition such as flames, sparks or impact from light blows.
I have hea... |
In practice, how dangerous is liquid oxygen as an oxidizing agent? |
This just looks like an arbitrary distinction they made in the ontology between 'short chain' acyl-CoAs and 'long chain'. As you can see, the 3-hydroxypalmitoyl chain is somewhat longer (16C) than the others. It stands to reason that the creators of the ontology have decided to subdivide hydroxy fatty acyl-CoAs into th... |
I'm a gold smith and I want to start experimenting with non-standard metal-alloys. Now high school is a long time ago for me so while I think I've got this right, I'm just not as sure as I should be when working with precious metals costing 40 dollar a gram. So could anyone confirm that what I'm doing is right:
I ha... |
From [Wikipedia][1]
> Cosmeceuticals refers to the combination of cosmetics and
> pharmaceuticals. Cosmeceuticals are cosmetic products with
> **biologically active ingredients** purporting to have medical or
> drug-like benefits.
I was wondering what ingredients being "biologically active" means?
In cosmet... |
I'm a gold smith and I want to start experimenting with non-standard metal-alloys. Now high school is a long time ago for me so while I think I've got this right, I'm just not as sure as I should be when working with precious metals costing 40 dollar a gram. So could anyone confirm that what I'm doing is right:
I ha... |
I've seen people arguing for some questionable "miracle cure-all" alternative medicines not scientifically, but by their own logic. A common claim is, that if a compound looks very similar to an important compound found in our body, it must be very beneficial. By looks very similar I mean the drawings of their structur... |
Are there notable organic compunds which look very similar but have very different properties? |
> **Possible Duplicate:**
> [Why are many drugs in the hydrochloride form?](http://chemistry.stackexchange.com/questions/689/why-are-many-drugs-in-the-hydrochloride-form)
<!-- End of automatically inserted text -->
Many uncharged organic compounds are sold in solid phase with HCl conjugate - e.g. the antihistamin... |
I'm a gold smith and I want to start experimenting with non-standard metal-alloys. Now high school is a long time ago for me so while I think I've got this right, I'm just not as sure as I should be when working with precious metals costing 40 dollar a gram. So could anyone confirm that what I'm doing is right:
I ha... |
I'm working with Poly(allylamine hydrochloride), and I found that the chemical formula is
$$(C_3 H_7 N)_n \cdot HCl$$
But I need a diagram like [THIS][1] But more explicit. I mean with the carbons, where they are exactly? |
What is the specific structure of Poly(allylamine hydrochloride) $(C_3 H_7 N)_n HCl$? |
There were ninety original elements on the Periodic Table. Over time, new ones were founded and put on. However, they were all either the original elements experimented on. For example, [Plutonium was discovered by deuteron bombardment of uranium][1]. Therefore, I would like to know: **How were the rest of the elements... |
Where did the rest of the elements come from? |
I'm running [gel permeation chromatography][1] (GPC) of a polar, uncharged polymer (acrylamide-based) in a polar solvent ([dimethylformamide][2]). The literature recommends adding a salt to the eluent; for my particular experiment, I'm using 0.05 M LiBr. Other salts are reported in the literature, both for this eluent/... |
Why should I add lithium bromide to my GPC eluent? |
Many uncharged organic compounds are sold in solid phase with HCl conjugate - e.g. the antihistamine [diphenhydramine.HCl][1] or the derivitizing agent [pentafluorobenzyl hydroxylamine.HCl][2], among many others. Assuming the compound will be dissolved at relatively low concentrations in a buffered medium (for instance... |
> **Possible Duplicate:**
> [Why are solid phase organics often conjugated to HCl?](http://chemistry.stackexchange.com/questions/2627/why-are-solid-phase-organics-often-conjugated-to-hcl)
<!-- End of automatically inserted text -->
I'm wondering why a lot of drugs are in this hydrochloride form.
E.g.,
+ Cet... |
I'm working on some combustion problems using [Cantera][1] and I can't find references for the thermodynamic or transport properties for many of my chemical species. I'm looking for NASA-7 or NASA-9 curve-fits for the thermodynamics, although if there is another equation format that exists, I will make it work. And I ... |
I'm working with Poly(allylamine hydrochloride), and I found that the chemical formula is
$$(C_3 H_7 N)_n \cdot HCl$$
But I need a diagram like [THIS][1] But more explicit. I mean with the carbons, where they are exactly?
[1]: http://www.sigmaaldrich.com/medium/structureimages/96/mfcd00084396.png |
I was learning about galvanic cells and I had a problem understanding why electrons do not travel through the electrolyte solutions themselves ,and why do they prefer to travel through metals ,therefor can electrons travel through an electrolytic solution ?Imagine that in a galvanic cell ,we don't have the wiring betwe... |
I was learning about galvanic cells and I had a problem understanding why electrons do not travel through the electrolyte solutions themselves, instead preferring to travel through metals. Can electrons travel through an electrolytic solution?
Imagine a galvanic cell, without the wiring between the two electrodes an... |
Why don't the electrons move through the electrolyte (instead of the circuit) in a galvanic cell? |
I have a question about electrical potential in galvanic cells ,suppose that we have only half a cell wich means that we have only one Ox/Red couple (one metal and the other as ionic solution ...)clearly nothing will happen ,suppose that we put a wire between the metal and the ground .The ground has no voltage while th... |
Can we create a galvanic cell with only half a cell connected to the ground? |
Recently someone is claiming that the laminar wood panels used for building our new primary school contains a "carcinogenic and dangerous compound", namely phenolphthalein.
I couldn't find any evidence of it being used as that on the net.
Could you confirm my findings?
Thank you |
Is phenolphthalein used in laminar wood construction panels? |
I'm running [gel permeation chromatography][1] (GPC) of a polar, uncharged polymer (acrylamide-based) in a polar solvent ([dimethylformamide][2]). The literature recommends adding a salt to the eluent; for my particular experiment, I'm using 0.05 M LiBr ([example][5]). Other salts are reported ([Sodium Sulfate][4], for... |
My chemistry is not good enough to solve this problem, and it's driving me crazy.
At my job, a sales agent approached me to be their representative in my area for their product. It's a product that when mixed with diesel or gasoline it reduces carbon emissions in the vehicle to almost 0.
Now this seems impossibl... |
How can vehicle carbon emissions realistically be reduced to almost 0? |
My chemistry is not good enough to solve this problem, and it's driving me crazy.
At my job, a sales agent approached me to be their representative in my area for their product. It's a product that when mixed with diesel or gasoline it reduces carbon emissions in the vehicle to almost 0.
Now this seems impossibl... |
My chemistry is not good enough to solve this problem, and it's driving me crazy.
At my job, a sales agent approached me to be their representative in my area for their product. It's a product that when mixed with diesel or gasoline it reduces carbon emissions in the vehicle to almost 0.
Now this seems impossibl... |
What would be the reaction mechanism for the reaction between epoxide and $\ce{H2SO4}$? |
Could it be that he meant phenol-formaldehyde resin?
http://en.wikipedia.org/wiki/Phenol_formaldehyde_resin
These resins are often used to bond wood chips. They contain unreacted formaldehyde and the resin decomposes slowly, giving off more formaldehyde, which is volatile and very toxic. This is a known health con... |
Could it be that he meant [phenol-formaldehyde resin][1]?
These resins are often used to bond wood chips. They contain unreacted formaldehyde and the resin decomposes slowly, giving off more formaldehyde, which is volatile and very toxic. This is a known health concern. Many companies offer indoor air testing for... |
Yes, diamond filters are used. Usually in the filtration of ethanol and water (vodka). All drinkable ethanol must be filtered through specialized carbon filters. so in the thinking that diamonds are formed from compressed carbon, therefore a diamond filter is the extreme sports of filtration. Whether its better?? I don... |
Why Platinum electron configuration is [Xe] 4f14 5d9 6s1? |
>Is it possible to recycle the oxygen efficiently enough to burn methane again and again?
Don't think so. Sounds a little like perpetual motion. Assuming you're burning the methane into $\mathrm{CO_2}$ and $\mathrm{H_2O}$, you would need a large supply of something that would regenerate the $\mathrm{O_2}$. The water... |
Why is the electronic configuration this:
<br>[Xe] 4f<sup>14</sup> 5d<sup>9</sup> 6s<sup>1</sup>
And not this?
<br>[Xe] 4f<sup>14</sup> 5d<sup>10</sup> 6s<sup>0</sup>
<br>or
<br>[Xe] 4f<sup>14</sup> 5d<sup>8</sup> 6s<sup>2</sup> |
Thanks for any help!
**Background**
I have a system with many species reacting. Some of the species associate/dissociate with others with a given Ke = 100.
Now, given that my system is expressed in terms of ordinary differential equations of the sort:
`dA/dt = v1 - v2`
`dB/dt = v3 - v4`
`...
`
w... |
##Background
I have a system with many species reacting. Some of the species associate/dissociate with others with a given $K_e = 100$.
Now, given that my system is expressed in terms of ordinary differential equations of the sort:
$$\frac{dA}{dt} = v_1 - v_2$$
$$\frac{dB}{dt} = v_3 - v_4$$
$$...$$
wh... |
What's that tangy smell on cheap plastic? |
I am doing my chemistry homework and I am supposed to write the products when strong acids react with water, but I am unsure of the physical state for hydronium ions. Should it be liquid (l) or aqueous (aq)?
Example:
HI(aq) + H<sub>2</sub>O(l) --> ?
Should it be...
H<sub>3</sub>O<sup>+</sup>(aq) + I<sup>-</... |
I am doing my chemistry homework and I am supposed to write the products when strong acids react with water, but I am unsure of the physical state for hydronium ions. Should it be liquid (l) or aqueous (aq)?
Example:
$\ce{HI(aq) + H2O(l) -> ?}$
Should it be
$\ce{H3O+(aq) + I^{-}(aq) }$ ?
Or should it be
... |
In essence what I'm asking is if the applications of Electrochemically activated water (ECA water) as a bactericidal-disinfectant is real and profitable (especially this last part). The principle at first seems very dull just take salt water through an electrolysis process and you get anolytes and catholytes, with disi... |
Is electrochemically activated water a real technology? |
Most cheap items (from china mostly) have a strong tangy odor to the plastics (or some resin, but i can mostly smell it on plastics). The smell is always consistent over a broad range or products and i get it for at least a decade. So i do not believe this is a one-off thing and i bet most people have experienced it. T... |
I am asked to identify the organic/inorganic products of a Sn1 reaction between 3-iodopentane and ethanol. I have identified correctly that the substrate is the 3-iodopentane, the leaving group is the iodide, and that the nucleophile is the ethanol. My problem is that I do not understand what the products will be, and ... |
What are my products in this Sn1 reaction, how do I know? |
I am asked to identify the organic/inorganic products of a Sn1 reaction between 3-iodopentane and ethanol. I have identified correctly that the substrate is the 3-iodopentane, the leaving group is the iodide, and that the nucleophile is the ethanol. My problem is that I do not understand what the products will be, and ... |
Before I can even begin to contemplate the products of a given Sn1 reaction, I need to be able to determine what my leaving group will be, which should be a species with a strong conjugate acid, and as I understand it the species should be relatively stable once it has left the substrate. Please correct me if I am maki... |
How should I Identify my leaving group in Sn1 reactions if there might be more than one option? |
I am asked to identify the organic/inorganic products of an [S<sub>N</sub>1 reaction ][1] between [3-iodopentane][2] and [ethanol][3]. I have identified correctly that the substrate is the 3-iodopentane, the leaving group is the iodide, and that the nucleophile is the ethanol. My problem is that I do not understand wha... |
What are my products in this SN1 reaction, how do I know? |
Before I can even begin to contemplate the products of a given [S<sub>N</sub>1 reaction][1], I need to be able to determine what my leaving group will be, which should be a species with a strong conjugate acid, and as I understand it the species should be relatively stable once it has left the substrate. Please correct... |
How should I identify my leaving group in SN1 reactions if there might be more than one option? |
This case (and similar cases) you need to think about the following:
1. When a leaving group leaves, only one bond is broken. By this logic, $\ce{OH}$ is a leaving group - it can leaving by the breaking of the $\ce{C} -\ce{O}$ bond. The alcohols you mention, $\ce{CH3OH}$ and $\ce{CH3CH2OH}$ require breaking two bon... |
R-OH + HBr -> R-Br + H2O
the mechanism goes by forming R+ carbocation
i want to ask if **R** is any alkyl group instead of methyl or ethyl, can the hydrogen of the the second carbon (carbon atom next to the carbon atom with which -OH is attached) be removed to form a double bond, sort of dehydration?? |
$\ce{R-OH + HBr -> R-Br + H2O}$
An $\ce{R+}$ carbocation is formed during this reaction.
If $\ce{R}$ is any alkyl group instead of methyl or ethyl, can the [beta hydrogen][1] to the hydroxy group be removed to form a double bond, similar to a dehydration??
[1]: http://en.wikipedia.org/wiki/Alpha_and_be... |
The other day I was dipping out Neapolitan(strawberry, vanilla, & chocolate) ice cream and noticed that the chocolate ice cream tended to melt faster than that of the vanilla and strawberry. I couldn't remember in which order I dipped the ice cream so I decided to do a controlled experiment with it the next time I dip... |
Why does chocolate ice cream melt faster than others? |
I just came across this reaction
$\ce{Na2S2O3 + 2HCl -> 2NaCl + SO2 + S + H2O}$
I was wondering if it was possible to predict the products of this reaction if I didn't know it (or any inorganic reaction for that matter).
Can we use arrow-pushing (as we do in organic chemistry) to get the products of an inorgan... |
List in order of increasing radius:
a) Rb, K, C5, Kr
For this one I got C, Kr, K, Rb
b) Ar, Cs, Si, Al
This I got: Ar, Si, Al, Cs
Does anyone know if this is correct? I don't have the solution for these in my book :S
Thanks very much! :D |
Considering the Sn1 reaction of (S)-2,3-dimethyl-3-pentanol, knowing that this molecule has a chiral carbon, should I always assume that both enantiomers are present, and therefore the products of a reaction will always have $2^n$ products for $n$ stereocenters on the substrate, **assuming that each stereocenter has eq... |
If I have a chiral substrate, should I always assume that both enantiomers are present? |
In this S<sub>N</sub>1 reaction there would be two products even if only one enantiomer reactions.
Enantiomerically pure (S)-2,3-dimethyl-3-pentanol reacts with HBr to produce both (S)-3-bromo-2,3-dimethylpentane and (R)-3-bromo-2,3-dimethylpentane in equal proportions as a racemic mixture.
ALSO, enantiomericall... |
Why is the electronic configuration of Platinum is [Xe] 4f<sup>14</sup> 5d<sup>9</sup> 6s<sup>1</sup> ?
And not this?
<br>[Xe] 4f<sup>14</sup> 5d<sup>10</sup> 6s<sup>0</sup>
<br>or
<br>[Xe] 4f<sup>14</sup> 5d<sup>8</sup> 6s<sup>2</sup> |
List in order of increasing radius:
a) Rb, K, C5, Kr
For this one I got C, Kr, K, Rb
b) Ar, Cs, Si, Al
This I got: Ar, Si, Al, Cs
Does anyone know if this is correct? I don't have the solution for these in my book :S |
I just came across this reaction
$\ce{Na2S2O3 + 2HCl -> 2NaCl + SO2 + S + H2O}$
I was wondering if it was possible to predict the products of this reaction if I didn't know it (or any inorganic reaction for that matter).
Can we use arrow-pushing (as we do in organic chemistry) to get the products of an inorgan... |
As the question title says, I would like to know what the physical and chemical properties are. If possible, please include examples. Since it seems to be related, I would also like to know what physical and chemical changes are. I believe that things such as crushing a can is a physical change, but I am not sure what ... |
What are physical properties and chemical properties? |
I am fully aware that the pKa is the pH at half the equivalence point, but are there some programs or methods I could use to accurately estimate the pKa without manually drawing lines on the graph? |
How can I find pKa from a titration curve? |
Far from 'only now' becoming viable, the production of disinfectant from electrolysis of salt water (brine) is not only 'real' it is [how bleach sold on supermarket shelves is produced][1]! Industrially, this is called the ['chor-alkali process'][2] and is well established for over 100 years. Recent innovations in ter... |
Far from 'only now' becoming viable, the production of disinfectant from electrolysis of salt water (brine) is not only 'real' it is [how bleach sold on supermarket shelves is produced!][1] Industrially, this is called the ['chor-alkali process'][2] and is well established for over 100 years. Both chlorine and sodium ... |
The general answer to this question is no, one cannot simply predict the products of any reaction. How do we know that one of the products is not $\ce{S2O6^{2-}}$ or perhaps even $\ce{S2O5Cl2^{2-}}$?
The best that can be done without any guidance from experiment is to compute the thermodynamically favored products.... |
Can someone draw the reaction that leads to the generation of HOCl when above is dissolved in water? |
How does dichlor-n triazene trione (dichloroisocyanuric acid) generate hypochlorous acid when dissolved in water? |
##Rephrasing:
The following reactions are a small example of my big system
$$(1) A + B <-> AB$$
$$(2) AB -> CB$$
$$(3) A -> C$$
$$(4) C + B <-> CB$$
with
$$\ce{\frac{[AB]}{[A][B]}} = 100 = K_e$$
$$\ce{\frac{[CB]}{[C][B]}} = 100 = K_e$$
I know the rate constants for reactions (2) and (3), and I know t... |
##Rephrasing:
The following reactions are a small example of my big system
$$(1) A + B \rightleftharpoons AB$$
$$(2) AB \rightarrow CB$$
$$(3) A \rightarrow C$$
$$(4) C + B \rightleftharpoons CB$$
with
$$\ce{\frac{[AB]}{[A][B]}} = 100 = K_e$$
$$\ce{\frac{[CB]}{[C][B]}} = 100 = K_e$$
I know the rate c... |
##Rephrasing:
The following reactions are a small example of my big system
$$(1)\ \ce{A + B <=> AB}$$
$$(2)\ \ce{AB -> CB}$$
$$(3)\ \ce{A -> C}$$
$$(4)\ \ce{C + B <=> CB}$$
with
$$\ce{\frac{[AB]}{[A][B]}} = 100 = K_e$$
$$\ce{\frac{[CB]}{[C][B]}} = 100 = K_e$$
I know the rate constants for reactions... |
What is the significance of enclosing marks in chemical names in determining the uniqueness of a substance (organic and inorganic)?
Can a simple change in the type of enclosing mark used indicate that we are dealing with a different substance or does it just mean that the names were written slightly differently (or ... |
What is the significance of different enclosing mark types in chemical names for differentiating between substances? |
What is the significance of enclosing marks in chemical names in determining the uniqueness of a substance (organic and inorganic)?
Can a simple change in the type of enclosing mark used indicate that we are dealing with a different substance or does it just mean that the names were written slightly differently (or ... |
What is the significance of enclosing marks in chemical names in determining the uniqueness of a substance (organic and inorganic)?
Can a simple change in the type of enclosing mark used indicate that we are dealing with a different substance or does it just mean that the names were written slightly differently (or ... |
What is the significance of enclosing marks in chemical names in determining the uniqueness of a substance (organic and inorganic)?
Can a simple change in the type of enclosing mark used indicate that we are dealing with a different substance or does it just mean that the names were written slightly differently (or ... |
I've been studying the roles of hydroxide & hydronium in acids and bases, and it was mentioned that a hydroxide ion (OH<sup>-</sup>) has a negative charge. Can someone give me a layman's explanation of what causes this charge?
Since hydrogen and oxygen are sharing a covalent bond, is the charge negative because an e... |
Why is does a hydroxide ion have a negative charge? |
What is the correct name for a reaction like this?
4MnO2 ---500 C---> 2MnO3 + O2 ^
Is it a synthesis, or a Decomposition?
I tried to find it out with http://en.wikipedia.org/wiki/Chemical_reaction but i did not get the link between the formula and the nomenclature as it seems to be both. |
Are different enclosing mark types in chemical names needed to differentiate between substances? |
What is the correct name for a reaction like this?
>$$ \ce{ 4MnO2} \overset{500 \ ^{\circ}\text{C}}{\longrightarrow} \ce{2MnO3 + O2 ^}$$
Is it a synthesis, or a Decomposition?
I tried to find it out with http://en.wikipedia.org/wiki/Chemical_reaction but i did not get the link between the formula and the nome... |
Is it possible to synthesise ethers from carboxylic acids, and if so how? By ether I mean an ether in general (R-O-R'), not just specific examples.
I theorised one could perform Fischer esterification (ROH+R'COOH->RCOOR') and then perform Wolff-Kishner reduction on the carbonyl group. The problem with this theory is... |
Is it Possible to Synthesise Ethers from Carboxylic Acids? |
When hydrocarbons burn with little oxygen, carbon is produced. What form do these particulates of carbon come in? Is it a simple molecule like $S_8$, or a small fragment of a larger structure, like graphite? Why is it stabler to take this form than others?
|
What is the correct name for a reaction like this?
>$$ \ce{ 4MnO2} \overset{500 \ ^{\circ}\text{C}}{\longrightarrow} \ce{2Mn2O3 + O2 ^}$$
Is it a synthesis, or a Decomposition?
I tried to find it out with http://en.wikipedia.org/wiki/Chemical_reaction but i did not get the link between the formula and the nom... |
Why does the hydroxide ion have a negative charge? |
I, being of sound constitution and firm belief in the coulomb barrier, find palladium's absorption of hydrogen fascinating.
If I understand correctly, H2 in the presence of Pd readily dissociates as it dissolves into the metal. With the dissociation energy for the H-H bond being so large, how is this possible?
... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.