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What reaction took place? |
Okay, so I was fiddling about in the chemistry lab, and I added:
Sodium Nitroprusside (soln) $\small\ce{ Na_2[Fe(CN)_5NO] }$ with Potassium Ferrocyanide (soln) $\small\ce{ K_4[Fe(CN)_6] }$.
$\small\ce{ Na_2[Fe(CN)_5NO] }$ was a yellowish-reddish colour - actually don't remember the _exact_ colour, while $\small\... |
I diluted sulfuric acid in deionized water in order to get a 10% $\ce{H2SO4}$ solution.
I was going to use this solution as a cathode of a porous sample to measure its electrical properties.
However, this solution has a quite high resistivity (~200 ohm.cm DC).
I checked several sources that tell me that I shou... |
I use Sodium persulfate to etch a copper board to produce a PCB. I mix 1 dl sodium persulfate with 1 liter hot water. When the water get cold, I heat it up by microwave. After the microwave, I see such crystallized particles at the bottom of the jar. Please note that there were not any solid particles in the acid befor... |
**QUESTION**
Butane, C4H8 is burned in an engine with a fuel-rich air-fuel ratio. Dry analysis of the exhaust gives the following volume percents: CO2 = 14.95%, O 2 = 0%, CO = 0%, H2 = 0%, C4H8 = 0.75%, with the rest being N2. Higher heating value of this fuel is 46.9 MJ/kg. Write the balanced chemical equatio... |
**QUESTION**
Butane, C4H8 is burned in an engine with a fuel-rich air-fuel ratio. Dry analysis of the exhaust gives the following volume percents: $\ce{CO2} = 14.95%$, $\ce{O2} = 0%$, $\ce{CO} = 0%$, $\ce{H2} = 0%$, $\ce{C4H8} = 0.75%$, with the rest being $\ce{N2}$. Higher heating value of this fuel is 46.9 M... |
I've recently obtained a couple of electronics units which have suffered corrosion on their copper inductor coils. They were operated in conditions of intense humidity/heat and were placed near the sea. This has resulted in the complete failure in one of these units, where the inductor has come apart due to being eaten... |
If copper has started to corrode, can it stop? |
I remember that in my primary classed I had an experiment in science to show air contains 20% oxygen. The experiment involved taking a trough of water, lighting a candle in the middle of the trough and inverting a glass jar over the candle so that air supply for the candle is cut of. When candle extinguishes, water lev... |
From what I understand, the working agent inside a peltier cooler is Bismuth-Telluride. I've read a toxicity data-sheet regarding Bismuth-Telluride here:
http://www.espimetals.com/index.php/msds/50-bismuth-telluride.
If I were to use a peltier cooler inside a sealed cooling system, for example a thermoelectric ... |
I've recently had several jerry-cans of oil (awaiting disposal) topple over in the attached garage, and several rooms following influx of water following heavy rain. After the water level receded the floor is left with a thin layer of burnt oil.
Various sites on the net recommend using sawdust, baking soda etc. I'm ... |
Is there an efficient and effective way to clean oil from floor? |
I have submerged a iron nail in vinegar twice recently. What is puzzling me is the different results each time. The first time I submerged it, it was covered in rust. When I put it in the solution of vinegar, I got a red precipitate dissolved in the solution that I believe was Iron(II) and Iron(III) acetate. However, w... |
If you are ready to invest a lot of time to learn [Asymptote][1] you can use it to create 3D PDF documents from `pdb` files with it. [Here][2] is an example. It has the advantage that Asymptote has a good LaTeX integration and you can use the code directly in a LaTeX document. But it would be very messy to get the appe... |
**QUESTION**
Butene, C4H8 is burned in an engine with a fuel-rich air-fuel ratio. Dry analysis of the exhaust gives the following volume percents: $\ce{CO2} = 14.95%$, $\ce{O2} = 0%$, $\ce{CO} = 0%$, $\ce{H2} = 0%$, $\ce{C4H8} = 0.75%$, with the rest being $\ce{N2}$. Higher heating value of this fuel is 46.9 M... |
I have practical question.
How can I chemically remove Sn from Sn60Cu40 alloy?
|
How to "remove" Sn from Sn60Cu40 alloy? |
I have practical question.
How can I chemically remove $\ce{Sn}$ from $\ce{Sn60Cu40}$ alloy?
|
How to remove Sn from $\ce{Sn60Cu40}$ alloy? |
In High School I learned that an exothermic reactions releases energy, while an endothermic reaction needs energy to occur. Now I learned that there is a separate, somewhat similar classification scheme of exergonic and endergonic reactions.
What is the difference between these two classification schemes? Are exothe... |
Humans typically achieve combustion by starting a chemical reaction of a fuel (often a carbon $C$ containing fluid like methan $CH_4$), which is is brought into an an oxidizer ($O$ containing gas, like air). For exmaple, when you turn on a lighter.
>What would happen if the situation is turned around?
>We have ... |
Tight temperature controls are needed to ensure that the filament used in fabrication does not begin to "ooze". In places where the air pressure rises and drops during the course of the day there may be more or less ooze taking place. Controlling ooze is paramount to obtain better print quality.
Question: Given Bo... |
Does variations in air pressure affect the melting point of PLA and ABS while 3D Printing? |
**Background**
I use Sodium persulfate to etch a copper board to manufacture home made Printed Circuit Board (PCB).
On the etching powder's plastic, it is written that:
1.5-2dl of etch powder in 1 L of hot water or corresponding volumes
So I add 2 cup powder for 10 cup hot water. In the first time usa... |
When measuring avidity should you use the ligand concentration or the nanoparticle concentration? |
In molecular orbitals diagram, sigma and pi symbols are used. What do these symbols really mean? |
I have practical question.
How can I chemically remove $\ce{Sn}$ from $\ce{Sn60Cu40}$ alloy?
I want to get something like copper sponge this way.
Something like nanoporous gold produced from $\ce{Au50Ag50}$ for heat exchanger, but cheaper. |
I'm trying to remove water from an imidazolium salt (i.e. dry the salt). However I want to know if it is safe to remove the water under vacuum. Is it safe to condense water into a liquid nitrogen trap? Wouldn't the water freeze in the trap since the freezing temperature of water is 0 degrees Celcius? Just curious b... |
Is it safe to condense water into a liquid nitrogen trap? |
>The classifications *endothermic* and *exothermic* refer to transfer of heat $q$ or changes in enthalpy $\Delta_\mathrm{R} H$. The classifications *endergonic* and *exergonic* refer to changes in free energy (usually the Gibbs Free Energy) $\Delta_\mathrm{R} G$.
If reactions are characterized and balanced by solely... |
>The classifications *endothermic* and *exothermic* refer to transfer of heat $q$ or changes in enthalpy $\Delta_\mathrm{R} H$. The classifications *endergonic* and *exergonic* refer to changes in free energy (usually the Gibbs Free Energy) $\Delta_\mathrm{R} G$.
If reactions are characterized and balanced by solely... |
One use of a liquid nitrogen cold trap is to collect organic and water vapors that are removed from a system under vacuum. In this case, the vapors are collected as ices (solids). See [this reference](http://operatingexperience.doe-hss.wikispaces.net/file/view/Schlenk+Line+Safety.pdf) which has some useful informatio... |
I'll leave the science fiction/fantasy to more creative contributors, but I think your conditions can be replicated in our not-so-bizzaro world (although those over at the [Chemistry World Blog](https://www.youtube.com/channel/HCvMAz8uP7SYo) might be able to convince you that our world is a bit bizzare).
If you retu... |
I know that the wave function for a particle in a infinite potential well located at $0$ and $L$ which is $$\psi_{n}=\sqrt{\frac{2}{L}}sin\frac{n\pi x}{L}$$
but I want to find our wave function for the same situation where the walls are located at $-L$ and $+L$
I can write the Schrödinger equation but I am not a... |
I will answer this question by copying a passage out of the very good QM book bei Shankar (see [here][1]) which I can recommend wholeheartedly to anyone trying to learn quantum mechanics. I considered writing up a solution myself but since the passage answers your question exactly it would have been a waste of time and... |
I will answer this question by copying a passage out of the very good QM book bei Shankar (see [here][1]) which I can recommend wholeheartedly to anyone trying to learn quantum mechanics. I considered writing up a solution myself but since the passage answers your question exactly (ok, not quite exactly since the calcu... |
I will answer this question by copying a passage out of the very good QM book bei Shankar (see [here][1]) which I can recommend wholeheartedly to anyone trying to learn quantum mechanics. I considered writing up a solution myself but since the passage answers your question exactly (ok, not quite exactly since the calcu... |
I'm trying to figure out why the answer is C. Can anyone explain to me why that is the answer?
http://lookpic.com/O/i2/1095/GdTR2AY.jpeg
Copy and paste link in browser :) Clicking won't work |
Which compound reacts most slowly? |
You've been doing everything correctly so far - what we have now is the relative numbers in mols of each element in this 100g compound. As you correctly calculated, we have 1.25 mol of Fe and 0.94 mol of O2 - for the sake of simplicity we'll say it's 1.88 mol of O (I multiplied by 2).
Now we just take this into a c... |
The wave function for a particle in a infinite potential well located at $0$ and $L$ is $$\psi_n=\sqrt{\frac2L}\sin\frac{n\pi x}L$$
I want to find our wave function for the same situation where the walls are located at $-L$ and $+L$
I can write the Schrödinger equation, but I am unable to apply the boundary cond... |
You've been doing everything correctly so far - what we have now is the relative numbers in mols of each element in this 100g compound. As you correctly calculated, we have 1.25 mol of Fe and 0.94 mol of $\ceO2$ - for the sake of simplicity we'll say it's 1.88 mol of $\ce$O (I multiplied by 2).
Now we just take thi... |
You've been doing everything correctly so far - what we have now is the relative numbers in mols of each element in this 100g compound. As you correctly calculated, we have 1.25 mol of Fe and 0.94 mol of $\ce{O2}$ - for the sake of simplicity we'll say it's 1.88 mol of $\ce{O}$ (I multiplied by 2).
Now we just take... |
I'm trying to figure out why the answer is C. Can anyone explain to me why that is the answer?
![enter image description here][1]
[1]: https://i.stack.imgur.com/iMcYDm.jpg |
My smartphone gets over heated where I use mobile data for long period. Last day I found a cooler of an old cpu, the thing silver in colour to absorb heat(with eventually gives out heat as it has more surface area on the other side). I used to keep my phone above it and it gets cooled. So my question is whether it will... |
Would cooling of a battery using cooler affect its life time? |
Can anyone tell me the mechanism behind this reaction? |
I came across a naming convention which I haven't seen before. I let ChemDraw name the following compound for me and got a name containing lowercase "r" and "s" configurations.
<img src="https://i.stack.imgur.com/1qdUu.png" height="150">
Can someone tell me what this means and something about the actual conventio... |
What does lowercase r-s notation mean? |
Why doesn't cyclohexene have a cis-trans isomer whereas cyclodecene has one?
Is strain a factor? |
I am burning through some test prep and have a chem question that is troubling me. The questions is as follows:
How would you compare the acidity of the most acidic proton in each of the following molecules?
1)![enter image description here][1]
2)![enter image description here][2]
3)![enter image de... |
Question regarding comparing different chemical's most acidic protons? |
I'm currently building a toy chemistry model based around Gillespie's algorithm. Starting from a food set of {H,O,N,C} I let my system evolve, I have been storing my molecules as strings in SMILES format.
For instance:
[O] reacts with [H] --> [O]([H])
[O]([H]) reacts with [H] --> [O]([H])([H])
Using ... |
I'm currently building a toy chemistry model based around Gillespie's algorithm. Starting from a food set of {H,O,N,C} I let my system evolve, I have been storing my molecules as strings in SMILES format.
For instance:
[O] reacts with [H] --> [O] ([H])
[O] ([H]) reacts with [H] --> [O] ([H]) ([H])
Using sq... |
I came across the following relation in a book(written as a fact,with no proof),for a mixture of ideal gases both at the same pressure and temperature,the final volume of the mixture of gases after mixing is:
$ V_(mix) = \frac {M_1V_1 + M_2V_2}{M_1+M_2} $
where $ M_!,M_2 $ are molar masses of the individual gases an... |
Is this relation in case of a mixture of ideal gases valid? |
I have had a question that has been bugging me for a couple of years in my graduate school career, and I was wondering if perhaps someone could help explain it to me. Given an endpoint assay like this one I've shown below (an ELISA assay, but I assume it could work for any endpoint), how does the endpoint signal (the s... |
What does an endpoint saturated signal mean. How does it relate to equilibrium constant? |
I came across the following relation in a book(written as a fact, with no proof), for a mixture of ideal gases both at the same pressure and temperature. The final volume of the mixture of gases after mixing is:
$ V_{(mix)} = \frac {M_1V_1 + M_2V_2}{M_1+M_2} $
where $ M_!,M_2 $ are the molar masses of the individ... |
How to measure amount of oxygen in container? |
I'm experimenting with synthesis in microreactors and I'm using 2 reactants. I'd like to estimate the Reynolds number of the flow containing two miscible fluids. I have the values of their properties (density, viscosity, flowrate).
Do I just average both property values for both liquids or is there a more intricate ... |
I am currently investigating the assembly of gold nanoparticles in a mixture of water and oil. The thing is the following: If we have gold nanoparticles (35nm diameter) dispersed in water and we put some oil on it. After that we shake it, then the gold will be kept between the layer between water and oil and now I was ... |
Say you are given a set of particular elements, such as Dy, C, I, Er, P; is it possible to determine whether a compound exists with all of the given elements and no more?
If not, is it possible to find this out if given the number of a particular element, such as; two hydrogen and one oxygen where you could come to... |
Can you determine whether a compound can form given particular elements? |
When a battery is subject to overcharging or overdischarging (including attempts to recharge a primary cell), it may vent hydrogen. It seems that every type of electrochemical battery I've read about or used *specifically emits hydrogen* under these circumstances.
Why is hydrogen emitted in all cases, and not some ... |
Why do batteries specifically vent *hydrogen* in the event of abuse? |
I'm trying to figure out the patterns for Ionization Energies. I am familiar with the periodic trend, however things become quite different when we hit the 1st I.E. For example, Na has an I.E(1) of 495.8 kJ while its second I.E. rockets up to 4562 kJ while the atoms towards the right are much lower than this. The trend... |
How to measure amount of oxygen in air? |
This is untested, but I think it might work. You could light some fuel on fire inside the closed container and see how much of it burns (just put the cup of fuel on a kitchen scale) before it dies out and than back calculate how much oxygen was present. Preferably you should take a fuel that burns easily to make sure t... |
I'm not a chemist, but I need some insight into chemical thermodynamics. In the book that I'm reading [(Nevers, 2012)][1], equation (4.28) relates the chemical potential of a **pure species** to it's Gibbs energy per mol:
$\mu_a^{(1)} = \bigg( \frac{\partial G}{\partial n_a} \bigg)_{T,P,n_b...} = g_a^{(1)}$
where... |
Why is partial molar Gibbs energy the same as Gibbs energy per mol for a pure species? |
Im not chemist, and I'm looking for easiest way to measure how much oxygen plant in closed container will produce per hour (edit or few hours - for better accuracy).
My first idea was to measure percent of oxygen in air with automotive lambda sensor.
However I don't expect good precision of measurement like this... |
How to measure amount of oxygen (or carbon oxide) in air? |
![enter image description here][1]
Log 10 pg / ml
I do not understand the scale. How do I convert this to a standard concentration (without the logs)?
[1]: https://i.stack.imgur.com/MfqyS.png |
What does this scale mean? |
I'm not a chemist, but I need some insight into chemical thermodynamics.
In the book that I'm reading [(Nevers, 2012)][1], equation (4.28) relates the chemical potential of a **pure species** to it's Gibbs energy per mol:
$\mu_a^{(1)} = \bigg( \frac{\partial G}{\partial n_a} \bigg)_{T,P,n_b...} = g_a^{(1)}$
w... |
Why partial molar Gibbs energy and Gibbs energy per mol are equal? |
Why are partial molar Gibbs energy and Gibbs energy per mol equal? |
I found [this reaction][1] of $NH_4Cr_2O_7 + HgSCN + heat$ on youtube, and I'm curious as to how it works. I tried searching online, but didn't find much on it.
Thanks.
[1]: http://www.youtube.com/watch?v=QzjPva_MUAg |
The documentation for the indigo module can be found here
http://ggasoftware.com/opensource/indigo/api#inputoutput
So for instance if I have a molecule object for some SMILES string, e.g. "C", I wish to calculate the unbound electrons in each atom, for instance here the desired output would be [[atom=C, unbound_e... |
The documentation for the indigo module can be found here
http://ggasoftware.com/opensource/indigo/api#inputoutput
So for instance if I have a molecule object for some SMILES string, e.g. `"[C](=[O])"`, I wish to calculate the unbound electrons in each atom, for instance here the desired output would be `[[atom=C... |
How can I figure out the degeneracy of the d orbitals for a site that has a given point group? Specifically I'm interested in D3d and D3h, but it would be good to know how to do it in the general case. |
How do I determine the crystal field splitting for an arbitrary point group? |
I'm not a chemist, but I need some insight into chemical thermodynamics.
In the book that I'm reading [(Nevers, 2012)][1], equation (4.28) relates the chemical potential of a **pure species** to it's Gibbs energy per mol:
$\qquad\mu_a^{(1)} = \bigg( \dfrac{\partial G}{\partial n_a} \bigg)_{T,P,n_b...} = g_a^{(1)... |
A question was asked on another stackexchange site:
> [This is not nice perspective, but eventually it will happen. An astronaut falls out of spaceship because of damage caused by collision with other object, or because of suit decontamination. The fluids from the body would evaporate, and if any bacteria would surv... |
At what temperature will proteins and fats boil in a vacuum? |
If you already know the symmetry of your site then it is quite easy. In a lot of books (e.g. [this][1] one) and on [this][2] web site you can find the character tables of the point groups supplemented with two additional columns which show the transformation properties of the basis vectors (e.g. $\ce{p}$ orbitals), the... |
Find the difference in the maximum and mimimum oxidation state of S in (S4O6)2-.
My answer is 2 but the answer given is 5 can u help..? |
Find the difference in the maximum and mimimum oxidation state of S in $\ce{S4O6^{-2}}$.
My answer is 2 but the answer given is 5 can u help..? |
2D periodic systems can be mapped to toruses, but not spheres. This is easy to see because in a sphere, parallel lines always intersect. In the periodic system parallel lines never intersect.
Regarding your bonus question: I don't know of anyone who has tried to use a periodic model to study a sphere or torus. But p... |
Cathodic protection prevents the removal of positive form the metal surface by applying a negative charge to the metal.
Is is possible to prevent the reaction of an active metal (i.e. sodium) with water by aggressively forcing current into the metal using a DC source? We allow the "water" to be a dilute solution (~1... |
If one were to dissolve magnesium citrate (about 100mg) in water (about 70ml) and let the solution sit for 48 hours, would the solution be exactly the same as one dissolved and consumed right away?
How does one explain the difference in taste from a 48-hour solution and a 5-minute solution? |
Would dissolving a salt and letting it sit for 48 hours have an effect on the solution? |
What are 6 atoms commonly found in organic molecules? |
Can we determine weather a reaction is endothermic or exothermic? For example if we are given the following reactions:
SO2 + O2 ------------------ 2SO3
H2 + I2 -----------2HI
N2 + 3H2 ------------2NH3
Can we determine weather these reactions are endothermic or exothermic or do we have to just memorize this? |
Can we determine whether a reaction is endothermic or exothermic? For example if we are given the following reactions:
SO2 + O2 ------------------ 2SO3
H2 + I2 -----------2HI
N2 + 3H2 ------------2NH3
Can we determine weather these reactions are endothermic or exothermic or do we have to just memorize thi... |
Can we determine whether a reaction is endothermic or exothermic? For example if we are given the following reactions:
$$\ce{SO2 + O2 -> 2SO3}$$
$$\ce{H2 + I2 ->2HI}$$
$$\ce{N2 + 3H2 -> 2NH3}$$
Can we determine weather these reactions are endothermic or exothermic or do we have to just memorize this? Are ... |
What does it mean for our bond of interest if we have low bond length and high frequency? Trying to make this connection but am not understanding. If anyone could explain it intuitively, that would be much appreciated. |
What does it mean for our bond of interest if we have low bond length and high frequency? Trying to make this connection but am not understanding. If anyone could explain it intuitively, that would be much appreciated. Say we have the bond of interest of heptane which is C-C. What is the variable that us changing (bond... |
What does it mean for our bond of interest if we have low bond length and high frequency? Trying to make this connection but am not understanding. If anyone could explain it intuitively, that would be much appreciated. Say we have the bond of interest of heptane which is C-C. What is the variable that is changing (bond... |
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