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I am working on a problem in the context of an infinite symmetric potential barrier around the origin, with barriers at $x=- \frac{a}{2}$ and $x=\frac{a}{2}$. The wave function is a symmetric triangle-function:
$$
\Psi (x) = \begin{cases} 0 & x < - \frac{a}{2} \\ \sqrt{\frac{12}{a^3}} \left( \frac{a}{2} - \lvert x ... |
Which of the following has highest solubilty in water? |
I just read about non-metallic oxides in my textbook which says that non-metallic oxides are a compound formed of an oxide ion and a non-metal. It also said that they are acidic in nature. It gave examples of carbon dioxide and sulfur dioxide.
But then wouldn't hydrogen oxide (water) also be a non-metallic oxide an... |
is water a non-metallic oxide? and hence acidic in nature? |
![How to add a methyl group and an ethyl group to an alkyne with 2 terminal hydrogen separately.][1]
How to add a methyl group and an ethyl group to an alkyne with 2 terminal hydrogens separately?
[1]: https://i.stack.imgur.com/wDeHH.jpg |
How to do this catalytic hydrogenation reaction - adding 2 different gps to an alkyne with 2 terminal hydrogen? |
![How to add a methyl group and an ethyl group to an alkyne with 2 terminal hydrogen separately.][1]
How to add a methyl group and an ethyl group to an alkyne with 2 terminal hydrogens separately?
[1]: https://i.stack.imgur.com/wDeHH.jpg |
How to do this reaction - adding 2 different groups to an alkyne with 2 terminal hydrogens? |
1-octanol is polar due to the presence of the -OH group but it is immiscible with water. How is it possible? |
Which of the following has highest solubility in water?
A. $ Ca(OH)_2 $
B. $ Fe(OH)_3 $
C. $ Cr(OH)_3 $
D. $ Zn(OH)_2 $
And also please explain how can we predict their solubilities when we are not provided with their solubility products.
I know that calcium hydroxide is sparingly soluble. So it canno... |
Which of the following has highest solubility in water? |
Which of the following has highest solubility in water?
A. $ Ca(OH)_2 $
B. $ Fe(OH)_3 $
C. $ Cr(OH)_3 $
D. $ Zn(OH)_2 $
And also please explain how can we predict their solubilities when we are not provided with their solubility products.
I know that calcium hydroxide is sparingly soluble. So it canno... |
What is the maximum percentage of carbon allowed in stainless steel 202 so that it does not cause brittleness? |
When looking over an old organic midterm I came across this question.
![Question][1] ![Signals][2]
As you can see I got half of it right, but honestly I'm not sure how I got that one right or how you would answer this in general. Looking back at this now it appears that the first signal was split into a doublet ... |
I am working on a problem in the context of an infinite symmetric potential barrier around the origin, with barriers at $x=- \frac{a}{2}$ and $x=\frac{a}{2}$. The wave function is a symmetric triangle-function:
$$
\Psi (x) = \begin{cases} 0 & x < - \frac{a}{2} \\ \sqrt{\frac{12}{a^3}} \left( \frac{a}{2} - \lvert x ... |
My textbook ([Organic Chemistry, 2nd Ed. Hornback, Joseph][1]) states that if a hydrogen is located near the center of an aromatic ring it will experience an (often quite sizable) upfield shift, as seen in these images (borowed from aforementioned textbook)
Structure 1
![enter image description here][2]
Struct... |
This is clearly a Lewis acid/base problem.
Okay, I tried drawing sulfur trioxide out with three double bonds (as it is traditionally drawn). I know the oxygens are nucleophilic and the hydrogens on the water are electrophilic. Nucleophile attacks electrophile but that gives the central sulfur two lone pairs of elec... |
This question touches on whether sulfur is hypervalent (whether it expands its octet when bonding).
The first picture shows both sulfur with an expanded octet.
The problem is that in the first picture, we are supposed to end up with sulfuric acid, but we actually end up with sulfuric acid plus two lone pairs ... |
This question touches on whether sulfur is hypervalent (whether it expands its octet when bonding).
The first picture shows both sulfur with an expanded octet.
The problem is that in the top half of the below picture, we are supposed to end up with sulfuric acid, but we actually end up with sulfuric acid plus... |
How to calculate the rotational constants for different states from a stick spectrum? |
While studying Dipole moment in Organic Chemistry, I got stuck at a particular statement written in the book :
$\textbf{Symmetrical molecules without lone pair of electrons will have } \space \mu = 0.$
The main problem was,
why would they have $\mu$ =0 ?
What type of Symmetrical molecules are possible? ... |
Got a few issues with this:
![enter image description here][1]
Here is the Lewis Structure:
![enter image description here][2]
[1]: https://i.stack.imgur.com/RIfxE.png
[2]: https://i.stack.imgur.com/NX1GU.jpg
As we can see, we have five lone pairs on which a hydrogen proton can land and form ... |
So I've been going crazy with this question for the past 4 hours. I can't find much help in google cause it's not a traditional "find the velocity of the reaction" question. It's fine if you don't give me the answer, just teach me how to get there:
> A container at 30 degrees Celcius contains HNC(g) reacting to form... |
So I've been going crazy with this question for the past 4 hours. I can't find much help in google cause it's not a traditional "find the velocity of the reaction" question. It's fine if you don't give me the answer, just teach me how to get there:
> A container at 30 degrees Celcius contains HNC(g) reacting to form... |
So I've been going crazy with this question for the past 4 hours. I can't find much help in google cause it's not a traditional "find the velocity of the reaction" question. It's fine if you don't give me the answer, just teach me how to get there:
> A container at 30 degrees Celcius contains HNC(g) reacting to form... |
While studying dipole moment in organic chemistry, I got stuck at a particular statement written in the book :
> Symmetrical molecules without lone pair of electrons will have $\mu = 0.$
The main problem was, why would they have $\mu =0$ ?
What type of Symmetrical molecules are possible?
The book gave t... |
I've been going crazy with this question for the past 4 hours. I can't find much help in google cause it's not a traditional "find the velocity of the reaction" question. It's fine if you don't give me the answer, just teach me how to get there:
> A container at $30~^\circ\mathrm{C}$ contains $\ce{HNC_{(g)}}$ reacti... |
From time to time I do little pro bono lessons for second grade in math, physics and chemistry. Recently I came across this question.
In a container is 2 mol of SO3 (sulphur trioxide). This compound under certain conditions breaks down into SO2 (sulphur dioxide) and O2 (oxygen). At the same those two resulting compoun... |
From time to time I do little pro bono lessons for second grade in math, physics and chemistry. Recently I came across this question.
> In a container is $2~\mathrm{mol}$ of $\ce{SO3}$ (sulphur trioxide). This compound under certain conditions breaks down into $\ce{SO2}$ (sulphur dioxide) and $\ce{O2}$ (oxygen). At ... |
This is indeed a advanced exercise so maybe first you should made more easier exercises. In this case the student need to know **mole concept** and **equilibrium concept** that are not directly linked, the problem here is more related to equilibrium concept. For the future he/she should begin to reasoning following the... |
This is indeed a advanced exercise so maybe first you should made more easier exercises. In this case the student need to know **mole concept** and **equilibrium concept** that are not directly linked, the problem here is more related to equilibrium concept. For the future he/she should begin to reasoning following the... |
I'm performing a liquid liquid extraction on a 1 Liter water sample for GC analysis. The procedure calls for 3 extractions with $50~mL$ of $\ce{CH2CL2}$. Would one extraction with $150~mL$ produce different results? |
Why should one perform an extraction with multiple small portions of solvent as opposed to one large portion? |
I had a visit from an air conditioner repairman who brought with him a tank of refrigerant. He measured the system and determined that the pressure was about 20 psi too low. So he added refrigerant to the system until it was right.
When it came time to pay him, he said, "well I had to raise your system by 20 psi so ... |
Can a volume of gas be measured by change in PSI? |
Would it be valid to describe $N_2O_5$ isomers as cis or trans? As a matter of fact, does this molecule even have isomers, given that all its outer N-O bonds are resonance stabilized and therefore equal in length and strength?
Also for non-resonance stabilized compounds, would it be okay to describe say the N to O ... |
I've been going crazy with this question for the past 4 hours. I can't find much help in google cause it's not a traditional "find the velocity of the reaction" question. It's fine if you don't give me the answer, just teach me how to get there:
> A container at $30~^\circ\mathrm{C}$ contains $\ce{HNC_{(g)}}$ reacti... |
If in a structure like this
R - H - H - O - OR'
Where
H is cyclohexane ring
O is phenyl ring
R,OR' is alkyl group and Oxygen bonded to different alkyl group
If 2 linearly bonded Fluorines on top of O are moved to either H do you get the same effect?
What "effect" means i'm not sure, but this is related... |
Equivalent effect of alkoxy group? |
Are all polar molecules both nucleophilic and electrophilic, depending on which atom you are talking about? Take water for example. Oxygen bears the partial negative charge. Oxygen is nucleophilic. Because oxygen isolates electron density from the hydrogens, the hydrogens bear partial positive charges. So would the hyd... |
Consider a structure like this,
R - H - H - O - OR'
where H represents a cyclohexane ring, O is a phenyl ring, and R,OR' is alkyl group and oxygen bonded to different alkyl group.
If 2 linearly bonded fluorines on top of the phenyl ring are moved to either cyclohexane ring, do you get the same effect?
What "e... |
Liquid crystal structure: Equivalent effect of alkoxy group? |
I am trying to solve a question that asks to compare Q vs. K. K = 4.2, and Q = 1.0.
Problem Details:
> 2.0 mol of Samples of A, B, and C
> A + B = 2C
I know that the reaction equilibrium is to the right, but, from this information, how can I tell if it is far to the right or slightly to the right?
Thanks... |
How to tell how far equilibrium is? |
The Question I am trying to Solve: The pH of a 0.500 M solution of KC2H3O2.
My First Question: How would I go about calculating this?
My Second Question: Is the H3O in the middle of KC2H3O2 one Hydroxide ion?
Here is what I have attempted to do: Find the Conj Acid/Bases, write out a balanced equation, then tak... |
How to tell the pH of HC2H3O2? |
I am trying to solve a question that asks to compare Q vs. K. K = 4.2, and Q = 1.0.
Problem Details:
> 2.0 mol of Samples of A, B, and C
> $\ce{A + B \rightleftharpoons 2C}$
I know that the reaction equilibrium is to the right, but, from this information, how can I tell if it is far to the right or slightly... |
I'm making herbal and medicinal mushroom tinctures and extracts. Normally I'll use everclear but it isn't cheap and 95% alcohol. Also I don't know what that other 5% is. Is it just water?
Is there a way I can reduce alcohol to near 100% without a still? I've heard poring it over epsom salts through a few layer... |
What is a good way for a laymen to reduce alcohol to near 200 proof? |
The Question I am trying to Solve: The pH of a 0.500 M solution of $\ce{KC2H3O2}$.
My First Question: How would I go about calculating this?
My Second Question: Is the $\ce{H3O}$ in the middle of $\ce{KC2H3O2}$ one hydroxide ion?
Here is what I have attempted to do: Find the conjugate acid/bases, write out a b... |
I had a visit from an air conditioner repairman who brought with him a tank of refrigerant. He measured the system and determined that the pressure was about 20 psi too low. So he added refrigerant to the system until it was right.
When it came time to pay him, he said, "well I had to raise your system by 20 psi so ... |
What is a good way for a laymen to purify alcohol to near 200 proof? |
Compared to [anhydrous ethanol][1] with about 100 US\$/L -[everclear][2] seems to be a very nice and cheap substitute (30 US\$/L). It is perfectly safe to drink ***diluted*** so the remaining stuff should be almost only water. (Almost undetectable) Trace amounts of essential oils might be present, but as it is made fro... |
The Question I am trying to Solve: The pH of a 0.500 M solution of $\ce{KC2H3O2}$.
My First Question: How would I go about calculating this?
My Second Question: Is the $\ce{H3O}$ in the middle of $\ce{KC2H3O2}$ one hydroxide ion?
Here is what I have attempted to do: Find the conjugate acid/bases, write out a b... |
We had this question in a test and I am not sure of the answer
>**Q.** Temperature changes don't effect the extent of inter and intra molecular hydrogen bonding. State true or false.
I think that raising temperature would increase the kinetic energy of molecules and would thus lead to weakening of *inter* molecul... |
Effect of temperature on Hydrogen Bonding? |
Compared to [anhydrous ethanol][1] with about 100 US\$/L -[everclear][2] seems to be a very nice and cheap substitute (30 US\$/L). It is perfectly safe to drink ***diluted*** so the remaining stuff should be almost only water. (Almost undetectable) Trace amounts of essential oils might be present, but as it is made fro... |
According to this [source][1], graphite is used as anode material because carbon is easier to oxidize than $\ce{O^2-}$. The anodic oxidation of carbon
$$\ce{C + 2O^2- \rightarrow CO2 + 4e-}$$
proceeds more efficiently than the oxidation of $\ce{O^2-}$ at an inert anode
$$\ce{2O^2- \rightarrow O2 + 4e-}$$
$\... |
I'm currently working on a chemistry project in which I need to convert the first organic compound to the second organic compound.(see image) I only have a simple background in organic chemistry (and I haven't seen anything about reaction mechanisms yet) but I was guessing water could be used in this reaction?(to produ... |
Here is how I saw the Hamiltonian being written in one Quantum Mechanics book:
![enter image description here][1]
Well, That's all very nice and complicated, but looking at the last term and seeing the use of 'r' in there,![enter image description here][2]
[1]: https://i.stack.imgur.com/u9hLX.png
[2]... |
Why is the Schrodinger Equation for hydrogen atom like this? |
Best way to clean a gold-plated yoyo bearing? |
I'm building a home lab around _All Lab, No Lecture Illustrated Guide to Home Chemistry Experiments_ and I'd like to understand the chemistry that I'm doing a bit better. For example, here's an [iodine experiment][1].
> 1. Weigh out 2.0 g of potassium iodide and transfer it to a test tube.
>
> 2. Add about 1.5 mL... |
How to translate an experiment into equations? |
Most computer chips contain or are made of silicon. Why silicon? Why not copper or tellurium or some such? |
Why is Silicon used in computer chips? |
Here is how I saw the Hamiltonian being written in one Quantum Mechanics book:
![enter image description here][1]
Well, That's all very nice and complicated, but looking at the last term, and seeing the use of $r$ in there,![enter image description here][2]
[1]: https://i.stack.imgur.com/u9hLX.png
[2... |
Why does the Schroedinger equation for hydrogen atom look like this? |
>what is the r there?
r is the same in the potential energy term of the Hamiltonian as in the kinetic energy term of the Hamiltonian.
r is the distance from the proton.
> but isn't the position of the electron non-deterministic?
In the generally accepted Copenhagen interpretation of quantum mechanics, the p... |
I got a problem with this:
![enter image description here][1]
[1]: https://i.stack.imgur.com/pcURe.png
What if we stuck with the IUPAC name and called the isopropyl group a 1-methylethyl group? That would definitely _reverse_ the alphabetical priorities; because the substituents here on the hydrocarbon are... |
I got a problem with this:
![enter image description here][1]
[1]: https://i.stack.imgur.com/pcURe.png
What if we stuck with the IUPAC name and called the isopropyl group a 1-methylethyl group? That would definitely _reverse_ the alphabetical priorities; because the substituents here on the hydrocarbon are... |
For instance, if there is cup of water saturated with a salt to the point where any more added salt will just float around in the solution, are those undissolved salt molecules in equilibrium with the dissolved ones? For instance, do the undissolved ones become partially dissolved for a moment, while the dissolved ones... |
Do undissolved salts in saturated solvents enter equilibrium with the dissolved salts? |
I am doing a project where I heat up a container (around 500ml) filed with castor oil at room temperature. I want to add a pressure/safety valve that opens up when the castor oil reaches around 300 degrees Celsius (boiling temperature). In order to get the right valve I have to know how much the pressure increases with... |
I've been studying organic chemistry and I think trans fats are actually more stable than cis fats. This is because the steric hindrance (for trans) would be lower and the molecule energy would be lower too (more stable).
Why are unsaturated fats usually cis at room temperature if the steric hindrance is higher?
... |
Why unsaturated fats are usually cis? |
I learnt that given a reaction $A \to B$, the enthalpy change is given by,
$$\Delta H = \left( \begin{array}{c} \text{total enthalpy of}\\ \text{bonds broken}\end{array}\right)-\left( \begin{array}{c} \text{total enthalpy of}\\ \text{bonds made}\end{array}\right)$$
By convention, we keep the minus sign in the equ... |
I recently was in need of Zinc for an experiment. So I resorted to obtain it from some dry cell. But I womdered if it was pure Zinc or was it ZnO2 or anyother compoumd of Zn. It then occured to me that these questions arised, that I had knowledge of existence of pure Zn and its compounds. But how would its discovery ha... |
How elements are found to be in their elemental form? |
Im thinking il need a distilling(boiling) and collection flasks,a 3 way adapter with a thermometer in the top hole,and i was thinking of using an open vacuum adapter joining the lower end of the condenser to receiving flask. Does this sound ok? If so what type of condenser should i use ? |
What condenser can be used for simple distillation? |
I think I need some distilling (boiling) and collection flasks and a 3-way adapter with a thermometer. I was thinking of using an open vacuum adaptor to join the lower end of the condenser to the receiving flask. Does this sound ok? And if so, what kind of condenser should I use? |
I got a problem with this:
![enter image description here][1]
[1]: https://i.stack.imgur.com/pcURe.png
What if we stuck with the IUPAC name and called the isopropyl group a 1-methylethyl group? That would definitely _reverse_ the alphabetical priorities; because the substituents here on the hydrocarbon are... |
Yes. The two methods are equivalent.
You can try this with the dimerization of $\ce{NO_2}$ into $\ce{N_2O_4}$. In this reaction we form one $\ce{N-N}$ bond. Every other bond stays the same.
$\ce{2NO_2 \leftrightharpoons N_2O_4}$
If we calculate the enthalpy of the reaction through bond energies, we get the n... |
Yes. The two methods are equivalent.
You can try this with the dimerization of $\ce{NO_2}$ into $\ce{N_2O_4}$. In this reaction we form one $\ce{N-N}$ bond. Every other bond stays the same.
$\ce{2NO_2 \leftrightharpoons N_2O_4}$
If we calculate the enthalpy of the reaction through bond energies, we get the n... |
The difference between the Enthalpy of Reaction $\Delta_{\mathrm{r}} H$ and the Standard Enthalpy of Reaction $\Delta_{\mathrm{r}} H^{\ominus}$
------------------------------------------------------------------------
The standard value is not related to a standard temperature (although Standard Enthalpies of Reacti... |
Are molecules with bond orders < 1 stable? My professor commented that they were "barely alive" but what does he mean, scientifically? |
Are molecules with bond orders < 1 stable? My professor commented that they were "barely alive" but what does he mean, scientifically?
I know that molecules with fractional bond orders greater than one can exist - i.e. nitrogen oxide has a bond order of 2.5 (through MO calculations) and it exists just fine.
So ... |
I have a Graham condenser and tested it out by distilling water from salt water then I washed it and now I can't get either the coils or the jacket completely dry.
Any advice? If there isn't a better way I was thinking of popping it in the oven for a while to see if that'd dry it out the rest of the way. |
How do you dry a Graham condenser? |
Is the flip of the cis-isomer wrong? Specifically the image on the bottom right.
![enter image description here][1]
What I see is that on the cis-isomer in the first chair, we have an axial upward methyl group and an equatorial upward methyl group. When the ring flips we now have an equatorial upward methyl gr... |
Incorrect Ring Flip? |
My teacher said that if an atom is $\ce{sp^2}$ hybridized, then every atom it is bound to is _also_ $\ce{sp^2}$ hybridized.
1) Why is this true?
2) Is this even true?
I'm guessing this has to do with physical limitations. For example, consider a carbonyl oxygen. Oxygen is $\ce{sp^2}$ hybridized. The carbon the... |
Why does sp2 hybridization imply adjacent sp2 hybridization? |
My teacher said that if an atom is $\ce{sp^2}$ hybridized, then every atom it is bound to is _also_ $\ce{sp^2}$ hybridized.
1) Why is this true?
2) Is this even true?
I'm guessing this has to do with physical limitations. For example, consider a carbonyl oxygen. Oxygen is $\ce{sp^2}$ hybridized. The carbon the... |
The standard electrode potentials for the following redox couples are given as:
$E_0(Fe^{2+}/Fe) = x V, E_0(Fe^{3+}/Fe^{2+}) = y V$
What will be potential $E_0(Fe^{3+}/Fe)$ (in $V$)?
My approach: $Fe^{3+}+e^-+Fe^{2+}+2e^-\to Fe^{2+}+Fe$
So $E_0(Fe^{3+}/Fe)=(x+y)V$ |
Let's consider the five-atom ring part of the histidine molecule.
![enter image description here][1]
I was wondering why only one of the lone pairs on nitrogen is involved in the conjugate pi system. Specifically, I was wondering why it is that lone pair in particular instead of the other lone pair (there are ... |
Let's consider the five-atom ring part of the histidine molecule.
![enter image description here][1]
I was wondering why only one of the lone pairs on nitrogen is involved in the conjugate pi system. Specifically, I was wondering why it is that lone pair in particular instead of the other lone pair (there are ... |
Solid NaHCO3 is heated to 90°C. At equilibrium the total pressure of the gases produced is 0.545 atm. Calculate ΔG° at 90°C for the reaction
2 NaHCO3(s) ⇌ Na2CO3(s) + H2O(g) + CO2(g)
---
Using the ∆G° = -R*T*ln(K) formula, I did the work below:
∆G° = -(8.31)(273.15+90)*ln(0.545)
This gave me 1.83kJ/mol and t... |
Why is the equilibrium constant wrong for this Gibbs free energy problem? |
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