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How do tie-line slopes affect raffinate/extract envelope in ternary phase diagrams? |
I am an electronics guy with not so much knowledge of chemistry.
I would like to prepare a pH 7 buffer to test pH meters.
All web references I have found so far describing how to make a phosphate buffer use
disodium phosphate (Na<sub>2</sub>HPO<sub>4</sub>) and Monosodium phosphate (NaH<sub>2</sub>PO<sub>4</sub>) ... |
Can I make a pH 7 buffer from phosphoric acid and sodium hydroxide? |
I am having trouble understanding how d orbitals can have 5 orientations. Can someone please explain that do to me? |
I understand $d_{xy}$ and $d_{yz}$ and those orientations but ones like $d_{z^2}$ are very strange to me.
Can someone please explain that do to me? |
I understand $d_{xy}$ and $d_{yz}$ and those orientations but ones like $d_{z^2}$ are very strange to me.
Can someone please explain that to me? |
In class today, we were presented with the following molecule:
![hept-1-en-6-yne][1]
which we determined to be "**hept-1-en-6-yne**." The order of classification places alkenes above alkynes, so we get the appropriate numbering, but I'm wondering why, if that's the case, we don't end up with "**hept-6-yn-1-ene**?"
... |
Why is it -en-yne and not yn-ene? |
Azide is a fairly common ion, but why aren't there similar versions such as $P^-_3$ or $B_3^+$? Do they exist, is there something wrong with these ions as to make them more likely to just break apart rather than for ionic compounds. |
Analogies of azide? |
Well my book says that on heating- amorphous solids crystalline at some temperature. As far as I know , amorphous solids have a very disordered structure compared to crystalline solids and on further heating the level of disorder should increase. So why do they become more ordered or crystalline at high temperatures or... |
Amorphous to crystalline: Opposite trend? |
For metal complexes with $A_{2}$ or $E$ ground state terms there is angular momentum contribution to the magnetic moment which is generally positive for more than half-filled subshells and negative otherwise, and related to the spin-only magnetic moment by
>$m_{eff} = m_{SO}(1-\frac{\alpha\lambda}{\Delta})$
where ... |
In class today, we were presented with the following molecule:
![hept-1-en-6-yne][1]
which we determined to be "**hept-1-en-6-yne**." The order of classification places alkenes above alkynes, so we get the appropriate numbering, but I'm wondering why, if that's the case, we don't end up with "**hept-6-yn-1-ene**?"
... |
In class today, we were presented with the following molecule:
![hept-1-en-6-yne][1]
which we determined to be "**hept-1-en-6-yne**." The order of classification places alkenes above alkynes, so we get the appropriate numbering, but I'm wondering why, if that's the case, we don't end up with "**hept-6-yn-1-ene**?"
... |
Why is it -en-yne and not yn-ene? What is the explanation for this IUPAC specification? |
Except for the missing equilibrium arrow (these reaction are acid-base equilibria), they are fine. Or do you have any objections :) (what makes you doubt) ?
Also take @jerepierre's comment in account. This would probably be considered wrong if at an exam. |
Why the keto form of acteyl chloride is more stable even though the enol form is stabilized by the hydrogen bonding? |
At equilibrium, the rates of the forward and backward reaction become equal. In a reaction
A(s) giving B(g) + C(g)
Increasing the surface area of A increases the rate of the forward reaction, but the backward reaction is between two gases and is unaffected. By the time the rate of the backward reaction becomes equal... |
My teacher told me that order of lewis basic strength is inversely proportional to electro negativity. Comparing between iodide ion and chloride ion, chloride ion is more electronegative than iodide ion therefore iodide ion should be more basic than chloride ion but the order is reverse that is chloride ion is more bas... |
So according to the solutions there exist 7 different structural isomers 'containing 3 degree amines' for the molecular formula $C_6H_{15}N$
I tried and made a few, here are those
![enter image description here][1]
I have been trying since an hour and all I made were the repetitions of these 5 only. Could an... |
Which isomers I am missing here? |
According to the solutions there exist 7 different structural isomers 'containing 3 degree amines' for the molecular formula $\ce{C_6H_{15}N}$
I tried and made a few, here are those
![enter image description here][1]
I have been trying since an hour and all I made were the repetitions of these 5 only. Could ... |
What are all the structural isomers of a tertiary amine with the sum formula C6H15N? |
According to the solutions there exist 7 different structural isomers 'containing 3 degree amines' for the molecular formula $\ce{C_6H_{15}N}$
I tried and made a few, here are those
![enter image description here][1]
I have been trying since an hour and all I made were the repetitions of these 5 only. Could ... |
From what I understand is ingesting high amounts of sugar alcohols can lead to various effects such as abdominal pain and diarrhea, my question is, is there a certain amount of sugar alcohol if ingested cause drunkenness (even if it causes a person to be in a critical state or death) ?
|
Do sugar alcohols have the potential to get a person drunk? |
We can hydrogenate unsaturated compounds and measure the heat given off, this is called the **heat of hydrogenation**. As the following figure illustrates, if we hydrogenate the various **butene** isomers they all wind up producing the same molecule, **butane.**
![enter image description here][1]
[image source][2... |
Given a table like [this one][1], how can I determine the limiting conductivity of separate ions (as found [here][2])? I know that you can find the difference between for example K+ and Na+ if you know the limiting conductivity of KOH and NaOH, but how do you calculate the actual value for those two ions?
[1]: h... |
How to determine limiting conductivity of specific ions? |
Can someone please explain what exactly the difference between an intermediate and a transition state is?
I understand that they are formed as part of the process in converting the reactants to products in a chemical reaction. Other than that, al I know is that usually a transition state exists very briefly (if at all)... |
As explained by my instructor, Allylic Halides form highly stable Transition States. They are stable because they are:
- sp2 hybridized
- possess a conjugated system of pi bond and empty p orbital
However, if we consider the Sn1 mechanism, a carbocation intermediate is stabilized by resonance. Why is the formation o... |
Why do Allylic Halides prefer SN2 reaction over Sn1? |
As explained by my instructor,
> Allylic Halides form highly stable Transition States. They are stable because they are:
>
- $sp^2$ hybridized
- possess a conjugated system of pi bond and empty p orbital
However, if we consider the $S_N1$ mechanism, a carbocation intermediate is stabilized by resonance. Why i... |
How can the **main** product of the following reaction (2-bromo-3-chloro-2-butene + hydroiodic acid) be predicted, since Markovnikov's rule fails to distinguish:
$$\ce{H3C-C(Cl)=C(Br)-CH3~+~HI~->~?}$$
Note: This isn't a homework question. |
**You and your instructor are both correct, it is your premise that's wrong.**
Your instructor's explanation about the allyl double bond stabilizing the $\mathrm{S_{N}2}$ transition state is correct. The following figure shows the stabilizing interaction.
![enter image description here][1]
[image source][2]
... |
>My teacher told me that order of lewis basic strength is inversely proportional to electro negativity.
I agree with your teacher's guideline. Note that I said guideline. Lewis basicity (and acidicty) depend on a number of factors including:
- Strength of the corresponding Lewis acid or Lewis base and the stren... |
>My teacher told me that order of lewis basic strength is inversely proportional to electro negativity.
I agree with your teacher's guideline. Now, note that this cannot be your sole guideline. Lewis basicity (and acidicty) depend on a number of factors including:
- Strength of the corresponding Lewis acid or L... |
Why tautomers are considered to be the same chemical compound? |
Looking at the examples in [Tautomer on Wikipedia][1], it seems that the hydrogen needs to travel a significant distance (~20Å) for the interconversion to take place. What lets it happen so fast? Why interconversion is preferred over maintaining its position?
![Tautomer examples][2]
([source][3])
[1]: ... |
Why interconversion in tautomers is so rapid? |
Given a table like [this one][1], how can I determine the limiting conductivity of separate ions? I know that you can find the difference between for example K+ and Na+ if you know the limiting conductivity of KOH and NaOH, but how do you calculate the actual value for those two ions?
[1]: http://sites.chem.colo... |
Why do Allylic Halides prefer SN2 reaction over SN1? |
Why is the keto form of acteyl chloride more stable even though the enol form is stabilized by the hydrogen bonding? |
What is the reason for strong acids/bases dissociating in water? |
Given a table with equivalent conductivity of certain electrolytes, how can I determine the conductivity of separate ions? I know that you can find the difference between for example K+ and Na+ if you know the limiting conductivity of KOH and NaOH, but how do you calculate the actual value for those two ions?
EDIT:
... |
The easy answer:
It comes down to the strength of the bonds. Or that covalent bond strength is directly related to the bond dissociation energy and thus dissociation.
-------
*A little Physical Chemistry:*
In physical chemistry, they have something called bond dissociation ($D_o$).
From Atkins (9th Ed ... |
Why is the keto form of acetyl chloride more stable even though the enol form is stabilized by the hydrogen bonding? |
The easy answer:
It comes down to the strength of the bonds. Or that covalent bond strength is directly related to the bond dissociation energy and thus dissociation.
-------
*A little Physical Chemistry:*
In physical chemistry, they have something called bond dissociation ($D_o$).
From Atkins (9th Ed ... |
The easy answer:
It comes down to the strength of the bonds. Or that covalent bond strength is directly related to the bond dissociation energy and thus dissociation.
-------
*A little Physical Chemistry:*
(The following is how Pauling explained this.)
In physical chemistry, they have something called bo... |
A buffer with a pH of 4.44 contains 0.21 M of sodium benzoate and 0.12 M of benzoic acid. What is the concentration of [H ] in the solution after the addition of 0.050 mol of HCl to a final volume of 1.3 L?
So these are the steps that I have taken for this.
The Ka of Benzoic acid is 6.3 E-5
Thus: Ka=[C6H5COO-]... |
What is the concentration of H in the solution? |
Q: A buffer with a pH of 4.44 contains 0.21 M of sodium benzoate and 0.12 M of benzoic acid. What is the concentration of [H+] in the solution after the addition of 0.050 mol of HCl to a final volume of 1.3 L?
A: So these are the steps that I have taken for this:
The reaction is:
$$\ce{C6H5COOH +H2O -> C6H5COO... |
Q: A buffer with a pH of 4.44 contains 0.21 M of sodium benzoate and 0.12 M of benzoic acid. What is the concentration of $\ce{[H^+]}$ in the solution after the addition of 0.050 mol of $\ce{HCl}$ to a final volume of 1.3 L?
A: So these are the steps that I have taken for this:
The reaction is:
$$\ce{C6H5COOH +H... |
What is the concentration of H⁺ in the solution? |
There are van-der-Waals forces within non-polar molecules. I read it that is mainly due to the instantaneous movments of the electron cloud's distribution. When looking at symmetrical molecules like $CH_4$, the concept isn't hard to understand. But I have a question regarding the bioelectricity and action potential of ... |
Is momentary dipole in between cell membrane due to van-der-Waals forces? |
Is the momentary dipole in between a cell membrane due to the van-der-Waals forces? |
My textbook says that degree of dissociation= [HA]dissociated/[HA]initial * 100%.
However, it also says that citric acid has a degree of dissociation than acetic acid because citric is triprotic whereas acetic is monoprotic.
This reasoning doesn't fit with the top definition because, more protons donated doesn't n... |
What is degree of dissociation for polyprotic acids? |
I know that a magnetic dipole moment is given by $$\mu=\frac e{2m}I$$ and that the z component of angular momentum is $$m_j\hbar.$$ However, I have also seen that angular momentum $I$ is given by $$I=\hbar\sqrt{l(l+1)}.$$ Is this also the component in the z direction or is it different? Are both expressions for angular... |
Ignoring spin, consider an electron in a hydrogen 2p orbital, what is its orbital magnetic moment? |
I know that a magnetic dipole moment is given by $$\mu=\frac {-e}{2m}I$$ and that the z component of angular momentum is $$m_j\hbar.$$ However, I have also seen that angular momentum $I$ is given by $$I=\hbar\sqrt{l(l+1)}.$$ Is this also the component in the z direction or is it different? Are both expressions for angu... |
The best method for calibration would be a bath filled with a chemical at its melting point with a solid/liquid composition.
The constraints being that it must be hydrophobic and relatively non-corrosive and non-toxic with a melting point between (say) 20 °C and 60 °C. Needless to say, but I’ll say it anyway, the che... |
Is the attached 2 formula are e? z? trans? cis?
What is the rules for those type of cycloalkene geometric?
Thanks
![enter image description here][1]
![enter image description here][2]
[1]: https://i.stack.imgur.com/7qk9l.jpg
[2]: https://i.stack.imgur.com/sWqyA.jpg |
###What is the meaning of *cis* and *trans*?
*cis* means *on the same side* (or face), *trans* means *on the opposite side* (or face).
###Can I use *cis* and *trans* for cylic compounds?
Yes, you can describe the relative orientation of substituents on a ring using *cis* and *trans*, such as in the case of 1,3-dib... |
What are the configurations of these two compounds? Are they E or Z? Are they Cis or Trans?
What are the rules for these types of isomerism?
Thanks
![enter image description here][1]
![enter image description here][2]
[1]: https://i.stack.imgur.com/7qk9l.jpg
[2]: https://i.stack.imgur.com/sWqyA.jpg |
Polymorphism is defined as *the ability of a solid material to exist in more than one form or crystal structure*, whereas allotropy is defined as *the property of some chemical elements to exist in two or more different forms, in the same physical state, known as allotropes of these elements*. (From wikipedia).
In t... |
Couldn't there have been an entirely different negatively charged particle? What justified that assumption? |
How was it determined that the electron observed in the cathode ray experiments was the same particle that gave an atom its balancing negative charge? |
How was it determined that the electron observed in the cathode ray experiments was the same particle that gave an atom its balancing negative charge?
Couldn't there have been an entirely different negatively charged particle? What justified that assumption? |
Polymorphism is defined as *the ability of a solid material to exist in more than one form or crystal structure*, whereas allotropy is defined as *the property of some chemical elements to exist in two or more different forms, in the same physical state, known as allotropes of these elements*. (From wikipedia).
In t... |
###What is the meaning of *cis* and *trans*?
*cis* means *on the same side* (or face), *trans* means *on the opposite side* (or face).
###Can I use *cis* and *trans* for cylic compounds?
Yes, you can describe the relative orientation of substituents on a ring using *cis* and *trans*, such as in the case of 1,3-dib... |
Is it possible to create a galvanic cell without a half cell?
In the book I was reading, Illustrated Guide to Home Chemistry Experiments, the following lab (Laboratory 16.4) was suggested:
add 2M HCl and add copper metal to one end of the beaker, with magnesium at the other end. Then, add patch cables to connect ... |
Is it necessary to consider common ion effect when suppose a strong acid like HCl is added to water?
For example in this question: **10 ml 10^-6 M HCl** solution is mixed with **90 ml H2O**.pH will change approximately?
Normally by using **SV=constant** i get pH will change by **1 unit** (without taking common ion e... |
Why is pyridine so much more acidic than other similar imines (5.5 versus ~9, see picture)? Wouldn't delocalization of the positive charge into the aromatic system stabilize it and hence decrease acidity? Also the lone pair of pyridine is not delocalized into the perpendicular $\pi$-system and hence not any less availa... |
I recently stumbled across the substance "p,p′-terphenyldicarboxylic acid" in a scientific journal when recently reading about metal–organic frameworks.
Could someone explain the prefix p,p'- to me? |
Meaning of prefix p,p′-? |
I think this resembles the question [Confused about strong/weak dibasic and tribasic acids?][1]
Saying that the degree of dissociation (α) of citric acid is greater because it's triprotic is not correct. The degree of dissociation should be calculated for each dissociation separately. The degree of dissociation of c... |
How do quantum numbers change for ions?
*A sample question:* Give the set of four quantum numbers that could represent the electron lost to form the Rb **ION** from the Rb atom.
The answer given is n=5; l=0; ml=0; ms= +1/2. I chose the answer: n=4; l=1; ml=1; ms= -1/2.
I am looking for an explanation. I am c... |
How do quantum numbers change for ions?
*A sample question:* Give the set of four quantum numbers that could represent the electron lost to form the Rb **ION** from the Rb atom.
The answer given is n=5; l=0; ml=0; ms= +1/2. I chose the answer: n=4; l=1; ml=1; ms= -1/2.
I am looking for an explanation. I am c... |
My textbook says that degree of dissociation= [HA]dissociated/[HA]initial * 100%.
However, it also says that citric acid has a greater degree of dissociation than acetic acid because citric is triprotic whereas acetic is monoprotic.
This reasoning doesn't fit with the top definition because, more protons donated d... |
I'm studying for a chem exam and there are often questions of this form: What kind of inter-molecular interactions are important in (insert compound here). Then the possible answers are any combination of dipole-dipole, hydrogen bonding, and dispersion force.
My question is: When ever a molecule has hydrogen bonding d... |
How do you know what inter-molecular interactions are present? |
Which one of hydrogen and helium behaves more like ideal gas **in room temperature**...
I thought hydrogen gas would show more ideal behavior in room temperature because it has lighter mass (less no of electron) although it's diatomic, so there would be less attraction.
However, I saw one question on the book and t... |
Is it necessary to consider common ion effect when suppose a strong acid like HCl is added to water?
For example in this question: 10 mL of $10^{-6 } \ce{mol/L \ HCl}$ solution is mixed with 90 mL of $\ce{H2O}$. pH will change approximately?
Normally by using $SV=constant$ I get pH will change by **1 unit** (witho... |
I'm specifically talking about the decomposition of hydrogen peroxide by bovine catalase. The number of catalase molecule obviously doesn't change, so there's the same number of catalase molecule within an undiluted and a diluted solution. Also, seeing as water is not an enzyme inhibitor, and doesn't change the pH or t... |
When an enzyme is diluted with water, what is slowing down the rate of reaction? |
> […] there's the same number of catalase molecule within an undiluted and a diluted solution. Also, seeing as water is not an enzyme inhibitor, […]
**Q**: Why is dating between a fixed number of guys and girls more difficult on a large square packed with nuns than in a small club? ;)
**A**: It's mo... |
A task requires us to experiment water quality.
How would you reduce turbidity of a clay water sample with an effective and cost-effective method? |
> […] there's the same number of catalase molecule within an undiluted and a diluted solution. Also, seeing as water is not an enzyme inhibitor, […]
**Q**: Why is dating between a fixed number of guys and girls more difficult on a large square packed with nuns than in a small club (without the nuns)? ;... |
I want to take a training on computational works in chemistry. It should be of a short duration. Where in Europe I can find it? |
For example, would a box of baking soda in a fridge lose weight as it absorbs odor? How long would it take to drop 100g? |
Is there a visible change to baking soda when it reacts with odour? |
Did you check the offerings of the national chemical societies and their special interest groups?
In Germany, that would be the [CIC - Chemie Information Computer](https://www.gdch.de/netzwerk-strukturen/fachstrukturen/chemie-information-computer-cic.html) group of the [GDCh - Gesellschaft Deutscher Chemiker](https:... |
Could you explain the following statement in my chemistry book:
((Trigonal bipyramidal))
"Placing a lone pair in an axial position would put it at 90 degree to three other electron domains. Placing it in an equatorial put is at 90 degree to only two other domains, thus minimizing the number of strong repulsive int... |
How can placing a lone pair in axial position differs from that in equatorial in number of electron domains? |
I need help to determine the structure of unknown compound from my 1H NMR , 13C nmr and dept 135 spectrum?
I am a student and in my organic chemistry class we each had an unknown chemical from natural product. It dissolve in water.
On the bottom of the H NMR sheet it says:
Label --- Assigned Value --- Freq. Limits... |
I don't understand how to interpret graphs like the following:![enter image description here][1]
[1]: https://i.stack.imgur.com/fZGnb.png
Forget the difference between the Harmonic and Morse (I think I get that), It's more what the horizontal lines mean and what the boundary line means. I know that vibrationa... |
I need help to determine the structure of unknown compound from my 1H NMR , 13C nmr and dept 135 spectrum? <br/>
I am a student and in my organic chemistry class we each had an unknown chemical from natural product. It dissolves in water.
On the bottom of the H NMR sheet it says:
>Label --- Assigned Value --- F... |
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