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From [explainthatstuff.com][1]:
> Why doesn't glue stick to the tube?
> ---
> Adhesives are designed to work when they leave the tube—and not
> before. Different adhesives achieve this in different ways. Some are
> dissolved in chemicals called **solvents that keep them stable and
> non-sticky in the tube**.
... |
I'm on the email list of an Organic Chemistry help website, and they sent out this problem:
http://orgomadesimple.com/june-9-email-practice-problem/
This got me thinking: what if the nitrogen here was replaced with another oxygen atom? Would it still be *sp2* hybridized? Can oxygen molecules hybridize?
Thank... |
From [explainthatstuff.com][1]:
> Why doesn't glue stick to the tube?
> ---
> Adhesives are designed to work when they leave the tube—and not
> before. Different adhesives achieve this in different ways. Some are
> dissolved in chemicals called **solvents that keep them stable and
> non-sticky in the tube**.
... |
To anaesthetise the mucous membrane 2 separate drugs were given topically:
Oxybuprocaine hydrochloride and Lidocaine hydrochloride. The reason to use both of them seem to be beginning of action and its duration (the former starts faster but shorter, the latter starts later but longer acting).
If instead having th... |
Can Oxybuprocaine hydrochloride react with lidocaine hydrochloride? |
What is a good rule of thumb to use to determine if equilibrium is the appropriate assumption? I assume it is mainly to do with the time scales of the problem, meaning if the reaction time scales are very short, we could probably assume that we get to equilibrium very quickly. Is there an accepted metric for determin... |
When is equilibrium analysis appropriate? |
From [explainthatstuff.com][1]:
> Why doesn't glue stick to the tube?
> ---
> Adhesives are designed to work when they leave the tube—and not
> before. Different adhesives achieve this in different ways. Some are
> dissolved in chemicals called **solvents that keep them stable and
> non-sticky in the tube**.
... |
I'm on the email list of an Organic Chemistry help website, and they sent out this problem:
http://orgomadesimple.com/june-9-email-practice-problem/
This got me thinking:
- What if the nitrogen here was replaced with another oxygen atom?
- Would it still be $sp^2$ hybridized?
- Can oxygen molecules hyb... |
If 3,7 moles of Cu reacts with an excess of Cl2 and the exchange is 45% How many moles of CuCl2 can at maximum be created? |
Okay I will take a stab at this.
Consider the following **bond stretching parameters** in the TINKER FF file:
##################################
## ##
## Bond Stretching Parameters ##
## ##
##########... |
If $3.7~\mathrm{mol}$ of $\ce{Cu}$ reacts with an excess of $\ce{Cl2}$ and the exchange is 45% How many moles of $\ce{CuCl2}$ can at maximum be created? |
Well here's a question from my book:
> A solution containing one mole per liter of each Cu(NO<sub>3</sub>)<sub>2</sub>, AgNO<sub>3</sub>, Hg<sub>2</sub>(NO)<sub>3</sub> and Mg(NO)<sub>3</sub> is being electrolysed by using inert electrodes. The values of standard electrode potentials in volts(reduction potentials) a... |
Why isn't Mg deposited on the cathode after electrolysis? |
Okay I will take a stab at this.
Consider the following **bond stretching parameters** in the TINKER FF file:
##################################
## ##
## Bond Stretching Parameters ##
## ##
##########... |
>Why do we use the Kováts index?
The Kováts index is used to normalize GC data. [This Wikipedia page](https://en.wikipedia.org/wiki/Kovats_retention_index)(though not very long), sums up why you would want to do so.
Retention times of the same compound on even two different versions of identical instrument with ... |
If $3.7~\mathrm{mol}$ of $\ce{Cu}$ reacts with an excess of $\ce{Cl2}$ and the exchange is 45% How many moles of $\ce{CuCl2}$ can at maximum be created?
So I start with write the reaction formula
Cu + Cl2 = CuCl2
and then balance it.
2Cu + 2Cl2 = 2CuCl2
I know that I have 3,7 moles of Cu, which is 235,1202... |
HSO3 -> S2O6^2
The oxidation number of S on the left is +4 and +5 so when adding electrons to balance the oxidation number why is 2e- added to the right instead of one?
Why is 2 placed in front of the HSO3? |
For the half reaction HSO3- --> S2O6^2- why is it that 2e- are on the right hand side when balancing and not one electron? |
$\ce{HSO3 -> S2O6^{2-}}$
The oxidation number of S on the left is +4 and +5 so when adding electrons to balance the oxidation number why is 2e- added to the right instead of one?
Why is 2 placed in front of the $\ce{HSO3}$? |
For the half reaction HSO3- -> S2O6^2- why is it that 2e- are on the right hand side when balancing and not one electron? |
$\ce{HSO3- -> S2O6^{2-}}$
The oxidation number of S on the left is +4 and +5 so when adding electrons to balance the oxidation number why is 2e- added to the right instead of one?
Why is 2 placed in front of the $\ce{HSO3}$? |
Gasoline's power throughput per kg is $12,200 Wh/kg$ (Wikipedia.com). Are there any other fuels that have a higher power output that are not considered viable solutions as they are difficult to handle or have negative externalities?
Also what characteristics of their molecular structure give it the high energy throu... |
Disregarding negative externalities and other barriers, what are some fuels that have a higher power density than gasoline? |
This question is a little confusing. According to my teacher the entropy should decrease, but I think that sugar is crystalline first and later it dissolves, so the randomness increases and so the entropy should also increase. What is the correct answer? |
On adding sugar to water, does the entropy increase or decrease? |
Gasoline’s power throughput per kg is $12{,}200\,\mathrm{\frac{Wh}{kg}}$ (Wikipedia.org). Are there any other fuels that have a higher power output that are not considered viable solutions as they are difficult to handle or have negative externalities?
Also what characteristics of their molecular structure give them... |
Gasoline’s power throughput per kg is $12\,200\:\mathrm{Wh/kg}$ (Wikipedia.org). Are there any other fuels that have a higher power output that are not considered viable solutions as they are difficult to handle or have negative externalities?
Also what characteristics of their molecular structure give them the high... |
I am referring to the following three reactions. Two of these reactions are imaginary (M and X are imaginary).
$$
\begin{align}
\ce{X- + 2e -> X^{3-} \qquad &E^{\circ}_{X^{3-}/X^{-}}=\ 0.9V \ &---(a) }\\
\ce{2H+ + MO^{2+} + e -> M^{3+} + H2O \qquad &E^{\circ}_{{MO^{2+}}/{M^{3+}}}=\ 0.5V \ &---(b)\\ }
\ce{8H+ + M... |
Can the thermodynamic predictions of redox reactions based on E and dG contradict each other? |
In 2010 NASA announced the discovery of microorganisms that, after being treated in laboratory, could keep growing only using arsenic, instead of the (though very small amount of) phosphate they also had in nature.
However, this was confuted by further studies in the following two years.
Has there been success in fin... |
Has a non-carbon-based form of life been discovered since 2010? |
In 2010 NASA announced the discovery of microorganisms that, after being treated in laboratory, could keep growing only using arsenic, instead of the (though very small amount of) phosphate they also had in nature.
However, this was confuted by further studies in the following two years.
Has there been success in fin... |
If $3.7~\mathrm{mol}$ of $\ce{Cu}$ reacts with an excess of $\ce{Cl2}$ and the exchange is $45\,\%$, how many moles of $\ce{CuCl2}$ can at maximum be created?
So I start with write the reaction formula
$$\ce{Cu + Cl2 -> CuCl2}$$
and then balance it.
$$\ce{2Cu + 2Cl2 -> 2CuCl2}$$
I know that I have $3.7\ \mathrm{... |
Well here's a question from my book:
> A solution containing one mole per liter of each $\ce{Cu(NO3)2}$, $\ce{AgNO3}$, $\ce{Hg(NO3)2}$ and $\ce{Mg(NO3)2}$ is being electrolysed by using inert electrodes. The values of standard electrode potentials in volts (reduction potentials) are:
> - $\ce{Ag+/Ag} = +0.80$,
>... |
Are $\ce{C}$-chain molecules as in the picture likely to occur or do they exist at all?
![C-chain][1] and so on...
[1]: https://i.stack.imgur.com/jBzPt.png |
Well here's a question from my book:
> A solution containing one mole per liter of each $\ce{Cu(NO3)2}$, $\ce{AgNO3}$, $\ce{Hg2(NO3)2}$ and $\ce{Mg(NO3)2}$ is being electrolysed by using inert electrodes. The values of standard electrode potentials in volts (reduction potentials) are:
> - $\ce{Ag+/Ag} = +0.80$,
... |
$$\ce{HSO3- -> S2O6^{2-}}$$
The oxidation number of S on the left is +4 and +5 so when adding electrons to balance the oxidation number why is $\ce{2e-}$ added to the right instead of one?
Why is 2 placed in front of the $\ce{HSO3}$? |
![enter image description here][1]
[1]: https://i.stack.imgur.com/Be8rh.jpg
I am having some trouble going about this question. My first thought is to set up an ASTM separation equation to figure out the difference, but I do not know how to incorporate the reflux ratio which is (0.5).
ASTM: TBP 50% --> 550... |
Can a liquid which is saturated with a single solute, dissolve a different solute, or is saturation a universal thing? I ask because I’ve seen that different solutes have different points (amounts) at which they become saturated in water, for example, which caused me to think that maybe each solution was perhaps indepe... |
I am referring to the following three reactions. Two of these reactions are imaginary (M and X are imaginary).
$$
\begin{align}
\ce{X- + 2e -> X^{3-} \qquad &E^{\circ}_{X^{3-}/X^{-}}=\ 0.9V \ &---(a) }\\
\ce{2H+ + MO^{2+} + e -> M^{3+} + H2O \qquad &E^{\circ}_{{MO^{2+}}/{M^{3+}}}=\ 0.5V \ &---(b)\\ }
\ce{8H+ + M... |
Given a mixture of $\ce{HCl}$ and $\ce{MCl3}$ and the following dissociation constants for $\ce{M(OH)3}$, how can the concentrations of $\ce{HCl}$ and $\ce{MCl3}$ be determined separately by titrating this solution with a standard strong base (say, $0.1\:\mathrm{M}$ $\ce{NaOH}$) ? I want to be able to sketch the approx... |
Typically the antisymmetric stretch in IR spectroscopy is higher than the symmetric stretch for a given functional group. For example for $\ce{NO2}$ the antisymmetric stretch falls at $~1530 cm^{-1}$ compared to $1350 cm^{-1}$ for the symmetric stretch. Likewise $\ce{NH2}$ has a similar pattern ($3400 cm^{-1}$ antisymm... |
Typically the antisymmetric stretch in IR spectroscopy is higher than the symmetric stretch for a given functional group. For example for $\ce{NO2}$ the antisymmetric stretch falls at $\sim 1530\ \mathrm{cm^{-1}}$ compared to $1350\ \mathrm{cm^{-1}}$ for the symmetric stretch. Likewise $\ce{NH2}$ has a similar pattern ... |
Ultraviolet-Visible Spectroscopy
I understand the purpose behind infrared spectroscopy and mass spectroscopy, but UV-VIS doesn't make much sense to me.
Through research, I see that it as has to do with electron orbitals, and it has a relation to Beer's Law.
But what exactly can I learn about a molecule from its a... |
What is the purpose of UV-VIS Spectroscopy? |
> Why is $2$ placed in front of the $\ce{HSO3}$?
This is, of course, the elemental law of the conservation of mass. You have $x$ atoms that you put into your equation, you need to get $x$ atoms out again. While hydrogen and oxygen can be taken care of with water, you need to account for the sulphur immediately. Hen... |
To be honest this is a homework question. Below you can see a screenshot of it .
![enter image description here][1]
Below you can see what I have tried ,
![enter image description here][2]
I am stuck on this question. I don't know how to proceed further. So how can I solve this problem?
[1]: https://... |
A doubt on equilibrium question? |
The [broad absorption bands][1] of the electronic transitions observed in UV/Vis spectroscopy/spectrophotometry, as well as the myriad types of electronic transitions that might lead to absorption at a given wavelength, indeed make the technique much less powerful for identification of unknown compounds as compared to,... |
![enter image description here][1]
ATTEMPT:
In the first case, $\ce{H+}$ adds to the $\ce{OH}$ group, giving us a carbocation.The carbocation thus formed is exceptionally stable due to back bonding.I wonder why would it go under ring expansion eventhough the strain is not a factor here as the ring strain in a cy... |
Why is H2S2O7 stronger than H2SO4? |
$\Delta G = -n {\mathcal F} \Delta {\mathcal E} $
$\mathcal F$ is Faraday's constant, which physicists currently believe has been constant throughout the universe for all time. $n$ is the number of electrons transfered in an electrochemical reaction. For a given reaction, $n$ is also constant in all places and tim... |
$\Delta G = -n {\mathcal F} \Delta {\mathcal E} $
$\mathcal F$ is Faraday's constant, which physicists currently believe has been constant throughout the universe for all time. $n$ is the number of electrons transfered in an electrochemical reaction. For a given reaction, $n$ is also constant in all places and tim... |
Are (cyclic) $\ce{C}$-chain molecules as in the picture likely to occur or do they exist at all?
![C-chain][1] and so on...
[1]: https://i.stack.imgur.com/jBzPt.png |
![enter image description here][1]
ATTEMPT:
In the first case, $\ce{H+}$ adds to the $\ce{OH}$ group, giving us a carbocation. The carbocation thus formed is exceptionally stable due to back bonding. I wonder why would it go under ring expansion even though the strain is not a factor here as the ring strain in a ... |
tl;dr: how can I detect lead presence in bicycle paint dust?
Recently I started renovating a bicycle. The frame has been painted probably over 30 years ago, and despite holding well, big patches of rust are showing. So it's time to give the bike a new paint job.
Sadly it came to my attention that some bikes around t... |
Recently I started renovating a bicycle. The frame has been painted probably over 30 years ago, and despite holding well, big patches of rust are showing. So it's time to give the bike a new paint job.
Sadly it came to my attention that some bikes around that age have lead paint. Toxic, obviously.
I'm by no mea... |
I am referring to the following three reactions. Two of these reactions are imaginary ($\ce{M}$ and $\ce{X}$ are imaginary).
$$\begin{alignat}{3}
\ce{X- + 2e- \;&<=> X^3-} \qquad &&E^\circ_{\ce{X^3-}/\ce{X-}}=0.9\ \mathrm{V}\qquad &&&\text{(a)}\\
\ce{2H+ + MO^2+ + e- \;&<=> M^3+ + H2O} \qquad &&E^\circ_{\ce{MO^2+}... |
How to detect lead paint on a bicycle? |
$$\ce{HSO3- -> S2O6^2-}$$
The oxidation number of $\ce{S}$ on the left is +4 and +5 so when adding electrons to balance the oxidation number why is $\ce{2e-}$ added to the right instead of one?
Why is 2 placed in front of the $\ce{HSO3}$? |
Sorry for the super simple question.
Which of the following possesses the highest energy electron?
A) $\ce{Br-}$
B) $\ce{Ca^2+}$
C) $\ce{Cr+}$
D) $\ce{As}$
Don't bromine and arsenic have equally high energy electrons (i.e. in the $4p$ orbital)? My book says that arsenic is the correct answer (D). But... |
I think sulphuric acid will be the correct answer. I can't find answer. Please show your reasons.
___
**My attempt**: I've read that, for an oxi-acid, the oxidising number of the central atom shows the power of that acid. But here in this case, oxidising numbers of sulphur in sulphuric acid and pirosulphuric acid are... |
Recently I started renovating a bicycle. The frame has been painted probably over 30 years ago, and despite holding well, big patches of rust are showing. So it's time to give the bike a new paint job. And before that, I need to sand the frame and remove the current paint.
Sadly it came to my attention that some bik... |
Suppose I have the reversible reaction:
$$\ce{A +B⇌ C} $$
The reaction is at equilibrium with equilibrium constant $K$
I am told that if I increase the concentration of $\ce{B}$, the rate for the forwards reaction will exceed the backwards one. Fair enough.
I am also told that $K$ will necessarily increase... |
From [explainthatstuff.com][1]:
> Why doesn't glue stick to the tube?
> ---
> Adhesives are designed to work when they leave the tube—and not
> before. Different adhesives achieve this in different ways. Some are
> dissolved in chemicals called **solvents that keep them stable and
> non-sticky in the tube**.
... |
$\Delta G = -n {\mathcal F} \Delta {\mathcal E} $
$\mathcal F$ is Faraday's constant, which physicists currently believe has been constant throughout the universe for all time. $n$ is the number of electrons transfered in an electrochemical reaction. For a given reaction, $n$ is also constant in all places and tim... |
$\Delta G^\circ= -nFE^\circ $
$F$ is Faraday's constant, which physicists currently believe has been constant throughout the universe for all time. $n$ is the number of electrons transfered in an electrochemical reaction. For a given reaction, $n$ is also constant in all places and times.
Thus, $\Delta G^\circ$... |
$\Delta G = -n {\mathcal F} \Delta {\mathcal E} $
$\mathcal F$ is Faraday's constant, which physicists currently believe has been constant throughout the universe for all time. $n$ is the number of electrons transfered in an electrochemical reaction. For a given reaction, $n$ is also constant in all places and tim... |
$$\ce{HSO3- -> S2O6^2-}$$
The oxidation number of $\ce{S}$ on the left is +4 and +5 so when adding electrons to balance the oxidation number why is $\ce{2e-}$ added to the right instead of one?
Why is 2 placed in front of the $\ce{HSO3-}$? |
> My professor told us that $\ce{NaHCO3}$ will react to evolve
> $\ce{CO2}$ whenever the acidic nature of the reactant exceeds the
> acidic nature of benzoic acid.
But I want to know why? And is the
statement actually valid? (He didn't give us the reason)
> And in that case should $\ce{NaHCO3}$ react with 1,... |
> My professor told us that $\ce{NaHCO3}$ will react to evolve
> $\ce{CO2}$ whenever the acidic nature of the reactant exceeds the
> acidic nature of benzoic acid.
But I want to know why? And is the
statement actually valid? (He didn't give us the reason)
> And in that case should $\ce{NaHCO3}$ react with 1,... |
Is there a goal here? If you wanted to react aluminium with concentrated aq ammonia, you would get hydrogen but the rate would be proportional to temperature. However, this would be quite a poor way to create a reductive environment and as someone has already alluded, aluminium and sodium hydroxide or a strong mineral... |
At the eutectic point,what is effect of adding impurity on the boiling point? |
Why is it impossible in allene to have two pi-bonds in the same orientation?
=> Why isn't allene planar? (4 p electrons are in two 2x2 p-orbitals)
From my chemical intuition I would guess that there are 4 electrons in a p-system with three orbitals, but frankly I don't know how to allocate the lone pair electrons o... |
Why are the p-orbitals in allene perpendicular? |
Why is it impossible in allene to have two pi-bonds in the same orientation?
=> Why isn't allene planar? (4 $p$ electrons are in two 2x2 $p$-orbitals)
From my chemical intuition I would guess that there are 4 electrons in a $p$-system with three orbitals, but frankly I don't know how to allocate the lone pair elect... |
Why is it impossible in allene to have two pi-bonds in the same orientation?
=> Why isn't allene planar? (4 $p$ electrons are in two 2x2 $p$-orbitals)
From my chemical intuition I would guess that there are 4 electrons in a $p$-system with three orbitals, but frankly I don't know how to allocate the lone pair elect... |
At the eutectic point,what is effect of adding impurity on the melting point? |
HCl,Methanol,Hexane,Petroleum benzene
from more polar to less polar?
So I know,HCl has the most polarity.hexane I guess has the less.I guess the order should be like : HCl>Methanole>Petroleum benzene>Hexane
But Im not sure of the place of Petroleum benzene |
what is the Order of the following compounds based on polarity? |
> $\ce{HCl}$, Methanol, Hexane, Petroleum benzene
>
> from more polar to less polar?
So I know, $\ce{HCl}$ has the most polarity. Hexane I guess has the less. I guess the order should be like : $\ce{HCl}$>Methanol>Petroleum benzene>Hexane
But I'm not sure of the place of Petroleum benzene |
What is the order of the following compounds based on polarity? |
a)No effect
b)The melting point increases when the air pressure increase
C)The melting point decreases When the air pressure increase
the boiling point has inverse relation with vapor pressure of the liquid and direct relation with atmosphere(air) pressure. The melting point has direct relation with vapor ... |
The effect of air pressure on the "melting point"? |
> a)No effect
>
> b)The melting point increases when the air pressure increase
>
> c)The melting point decreases When the air pressure increase
The boiling point has inverse relation with vapor pressure of the liquid and direct relation with atmosphere (air) pressure. The melting point has direct relation wi... |
To be honest this is a homework question. Below you can see a screenshot of it .
![enter image description here][1]
Below you can see what I have tried ,
This is what I have got as the answer for Roman number one \begin{align}K_a &= \frac{[H^+(aq)] [A^- (aq)]} {[HA(aq)]} \end{align}
For Roman... |
Why allene cannot be described with an allyl system? |
- *How can I compare pH of an aqueous solution of SO2 with that of pure water
qualitatively?*
- *And I want to know what happen to the pH of an aqueous solution of SO2 if I aerate it by bubbling air through it .*
Probably we can have an aqueous solution of SO2 by dissolving it in water. Because we would hav... |
- *How can I compare pH of an aqueous solution of $\ce{SO2}$ with that of pure water
qualitatively?*
- *And I want to know what happen to the pH of an aqueous solution of $\ce{SO2}$ if I aerate it by bubbling air through it .*
Probably we can have an aqueous solution of $\ce{SO2}$ by dissolving it in water.... |
> a) No effect
>
> b) The melting point increases when the air pressure increases
>
> c) The melting point decreases When the air pressure increases
The boiling point has inverse relation with vapor pressure of the liquid and positive relation with atmosphere (air) pressure. The melting point has positive rela... |
Why is it impossible in allene to have two pi-bonds in the same orientation?
=> Why isn't allene planar? (4 $p$ electrons are in two 2x2 $p$-orbitals)
From my chemical intuition I would guess that there are 4 electrons in a $p$-system with three orbitals, but frankly I don't know how to allocate the lone pair elect... |
According to a question on my book,
> The following reaction mechanism has been proposed for the reaction of $\ce{NO}$ with $\ce{Br2}$ to form $\ce{NOBr}$<br />
$$\ce{NO(g) + Br2(g)<=>NOBr2(g)}$$
$$\ce{NOBr2(g) + NO(g) -> 2NOBr(g)}$$
If the second step is the rate determining step, what is the order of the reacti... |
What is the order of the reaction with respect to NO? |
Its really interesting to see the process of recycling of paper (as shown in picture) but at the same time I was thinking like for how many times can one sheet of paper can be recycled ?
![enter image description here][1]
[1]: https://i.stack.imgur.com/rUa0k.jpg |
How many times can we recycle one sheet of paper? |
> Why isn't allene planar?
Let's start by looking at the structure of allene and seeing what happens if we make it planar.
![enter image description here][1]
([image source][2])
As the above image shows, the 3 carbons in allene are linear (form a straight line) and the terminal hydrogens lie in orthogonal p... |
I understand the purpose behind infrared spectroscopy and mass spectroscopy, but UV-VIS doesn't make much sense to me.
Through research, I see that it has to do with electron orbitals, and it has a relation to Beer's Law.
But what exactly can I learn about a molecule from its absorbance/transmittance of UV/Visi... |
Which of the following statements is true?
$11.2$$ dm^{3}$ of Nitrogen at STP
A: has a mass of $14 $g.
B: consists of $0,5$ mol atoms.
My instinct was that the answer is $B$ because any gas has a volume of $22.4$ liters regardless of what the gas is. If $0.5$ mol of Nitrogen weights $11.2dm^{3}$ at STP, the... |
Does $11.2$$ dm^{3}$ of Nitrogen consist of $0.5$ moles at STP? |
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