Questions tagged [chemistry]
For engineering questions involving chemistry. For pure chemistry problems, please visit our sister site Chemistry Stack Exchange.
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How the choice of etchant can affect the severity of hydrogen embrittlement during pickling and passivation?
Following this question, I am trying to understand how/if the choice of acid we might use during the pickling and passivation of certain metals, can influence the severity of hydrogen embrittlement. ...
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Solar distillation of sump pump water and the issue of Radon gas
Lately I have been thinking about designing and building a solar-powered water distiller that would be placed close to my house in my backyard.
One thought that I have is installing a bypass valve on ...
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Why do Nickel Manganese Cobalt batteries wear out before Lithium Iron Phosphate batteries?
Do NMC batteries lithium plate faster? Does the Solid Electrolyte Interface (SEI) grow faster on NMC batteries? Do they heat up more and therefore the SEI grows faster? Does the Iron stabilize the ...
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Why don't we light the methane escaping from the NordStream pipeline?
The methane escaping from the NordStream pipeline for a few days now has a much more potent greenhouse effect than carbon dioxide. Burning methane gives us CO2.
The pipe won't be repaired before all ...
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Am I a chemist or a chemical engineer?
I apologise if this is the wrong place to ask. I tried asking on reddit but so far I didn't get a lot of answers/
It seems that in America these two degrees are considered separate. Not so much here ...
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I search for a solid material which dissolves in water very slowly, around 1 micrometre per hour measured from the water-contact-surface
I know there are some watersolutable Polymers out there like Polyvinylalcohol, but that would dissolve to fast. Is there some material that dissolves at around 1 micrometre per hour, regardless of pH ...
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What causes an increase in the elastic modulus in polymers?
I've learned that an increase in crystallinity increases the elastic modulus for polymers, however an increase in molecular weight does not, but why?
As an increase in crystallinity increases the ...
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How does evaporation impact enthalpy calculations?
For the following question, why should one calculated the heat transfer that occurs from going from 100°C to 36.6°C? As doesn't the water reach 100°C and then vaporize instead of coming back down to ...
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In electrochemistry, why is there a change in current when molecules bind?
From my limited understanding in electrochemistry, a set of electrodes are biased at a given potential and when there is a chemical reaction(antibody-antigen binding for example), a subsequent change ...
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Reactor tube material at moderately high temps (600-1000 C) with water vapor as primary constituent of flow
I work with a type of spectrometer (made by Picarro) that uses near-infrared lasers to measure the stable isotopic composition of water vapor. The samples measured are typically liquid water samples ...
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Would the below thermal generator work properly and provide surplus energy?
Since thermoelectric generators make electricity through thermal flux, could a device that mixes NaOH and HCl on one side (heat) and Ba(OH)2•8H2O and NH4SCN (cold) be efficient? Could it produce more ...
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Fastest possible mean (peak?) piston speed on a Diesel engine
On a Diesel engine running distillate fuel (the kind you run in cars, SUV's, trucks, trains, boats, and smaller ships), what are the theoretical and practical limits to maximum mean piston speed you ...
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Size characterization
Which technique can I use to characterize the size of my particles? They would be in the range of 50 μm to 300 μm. I have verified using a microscope, but I need a technique to analyse the size ...
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Heat Transfer in a tubular reactor with constant jacket temperature - impossible solution?
I have received from my professor the following problem:
A first-order exothermic reaction A -> B takes place in a tubular reactor (typical PFR). The tube is cooled to a constant wall temperature $...
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How to relate equilibrium constant and equilibrium conversion?
For the following gas phase reaction:
$$ A\leftrightarrow B $$
The concentration equilibrium constant ($K_c$) can be expressed as:
$$ K_c = \frac{c_B}{c_A} = \frac{\frac{F_B}{\vartheta}}{\frac{F_A}{\...
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How would you calculate the sedimentation rate of a coarse chemical suspension under gravity using a centrifuge?
If the sedimentation rate can be determined for a coarse chemical suspension or a suspension containing large particles (i.e., particles with radii between 100 to 200μm) in a medium like vegetable oil,...
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How long will it take to anneal at a lower temperature?
Someone is trying to anneal a brass casting to minimize the segregation of Zinc. He likes the results of annealing at 400 Celsius for 3 hours, but the high temperature produces problems with residual ...
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How much electricity does it take to polarize specific types of insulators?
as I hope you know, electric polarization is when you put an insulator in an electric field, and the nucleus and electron cloud go in an opposite direction. https://www.priyamstudycentre.com/2020/02/...
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CO2 production from sugar [closed]
Greenhouses often use burners for CO2 enrichment, which requires a source of liquid propane or natural gas.
The yeast fermentation process can also be used to create CO2 for a greenhouse by supplying ...
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Method of separating oxygen from a mixture of oxygen + carbon monoxide
I have a 99,9% oxygen, with 0,1% is CO. Is it possible to separate the CO from oxygen in this mixture? The closer the percentage to 0 for CO, the better.
I've read about separation of oxygen from air, ...
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Balancing Equation of Octane in combustion Chamber
Hey guys I am trying to balance out the combustion equation for reactants: Octane + Air
with products: CO2, H2O, N2, and O2; and 120% oh excess air.
My balancing equation looks like this:
$$ C_8H_{18} ...
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In case of solvation , Who converts gaseous ions to aqueous ? Why do we even have gaseous but not solid ions?
We take Nacl and dissolve it in water. There is formation of $Na^+$ and $Cl^-$ gaseous ions along with 2H+ and $Cl^{2-}$ aqueous ions.
Then , Na+ is attracted towards $Cl^{2-}$ and 2H+ is attracted ...
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Difficulty in understanding polarization? Is it only applicable for H and an electronegative element like chlorine? [closed]
There are two examples I have taken in diagram. In the first one , we have a cation and anion. They form an ionic bond due to which the cation has no electrons and the anion has 2 electrons. There are ...
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Difficulty in understand the meaning of standard enthalpy of formation
Standard enthalpy of formation is when one mole of compound is formed from its constituent elements.
Example : $H_2$(g) + $O_2$(g) —>$ H_2O$(L).
But we don’t say the same for $CaO + CO_2$ —> $...
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Specific CO2-Emissions of Natural Gas & Hydrogen Mix [closed]
consider I have a mixture of Hydrogen and Natural Gas.
The volumetric mixture is $\varphi_{H_2} = 70 \%$ and $\varphi_{NG} = 30 \%$.
So the $H_2$ makes up a mass fraction of
$$w_{H_2} = \frac{\rho_{...
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Is it possible to use direct air capture technology for CO2 on a non-commercial level?
CO2 is used as fertilizer in aquariums where it's brought into the water with diffusors from compressed form in cylinders. Direct Air Capture machines for CO2 have been presented for experimental geo-...
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Is molecular dynamics relevant for an undergraduate Mechanical Engineering degree? [closed]
I am completing my final year undergraduate study in Mechanical Engineering. I've had to have a scope change because my last project was not going to work with the pandemic. I've been given a project ...
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What is the field on engineering that combines chemistry and electronics together? [closed]
I am looking for a career advice as I am interested in chemistry and electronics at the same time but the universities somehow have the two as different major. Is there any branch of engineering that ...
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Can wet welding be done in mineral oil?
I'm interested in knowing whether or not submerged welding can be done in fluids other than water, specifically mineral oil in this case. The reason I want to know is that I'm looking into designing ...
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Help with Mass Flow Rate
I'm a beginner in chemical engineering so apologies in advance if this question is very basic!
The Problem
You are required to measure the mass and volumetric flow rate of a slurry stream. The slurry ...
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Is it possible to do purification of Sodium Sulphate and which companies do this? [duplicate]
If Sinter filter generates lots of Sodium Sulphate and then is there a way to make purification of this and which companies are already do this process?
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Why do Blast Furnace flue dust generates high rates of Zn (Zinc)?
The Blast Furnace flue dust contains high rates of Zn (Zinc). I'd like to know the reason behind this. The chemical reaction of Zn inside blast furnace dust. Why it's rates becoming high?
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How do I charge titanium dioxide particles submurged in black-dyed water in home?
My first thought was to charge the titanium dioxide particles by first charging a balloon by rubbing it on my hair and then touching the balloon to the titanium dioxide powder, but that would be ...
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How would I go about charging titanium dioxide for e-paper technology project?
I'm experimenting with rubbing a balloon on a silk (to get the electrons) and then touching the balloon to two small aluminium foil balls to see if they'll repel but they don't (if I do it with ...
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Is there an industrial process that makes use of photosynthesis?
When I was in school, photosynthesis was taught as this amazing biological process that took light and water and turned carbon dioxide into oxygen and carbon. It was implied that this was limited to ...
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What chemical can be used to restore synthetic rubber?
When rubber (I don't know the specifics, but I assume it's butyl rubber) gets old, it turns into one of two states usually:
It becomes sticky and gummy.
It becomes hard and brittle.
I'd like to know ...
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What is the mechanism of adsorption-desorption on biochar obtained from slow pyrolysis/ torrefaction?
Biochar is a major by-product from pyrolysis along with bio-oil and it is considered an important chemical feed-stock because of many light oxygenates.
I have read some papers on using bio-char use ...
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What's a good way to equalize pressure between 2 spaces without allowing gas exchange under normal circumstances?
I have a reaction chamber where gasses are injected to maintain a certain mixture. The container is sort of like a bell, where the bottom is submerged in water to make a seal.
The issue I have is ...
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What is the smoke made by the fogging machine? Is it harmful to humans?
What is the principle of a fogging machine ?
on what process a fogging machine depends ?
distillation or vapourization ?
what is the harmful effect of fogging machine ?
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Why does aluminum clad steel wire have high corrosion resistance?
Why do aluminum clad steel wires have high corrosion resistance despite being two dissimilar metals?
Does the aluminum act as a protective & sacrificial layer similar to zinc in galvanization or ...
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pH calculations for boiler water
For water steam cycle in a "combined cycle power plant" containing 3 boiler drums and dosing of 5% ammonia solution in the condenser. How can I calculate the pH of the boiler water in each of the ...
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Generic category of PBT thermoplastic
I'm an EE, but I'm working on a project at work where I need to venture into materials science & chemistry.
My question is, does thermoplastic, Polybutylene terephthalate (PBT), fall into any of ...
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Calculate the specific surface area of a mesoporous sample
I'm a nanoengineering student who's been stuck on the following problem for a few days. I've gone back over my professors slides, watched podcasts from an old professor, etc. etc., but don't ...
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Referencing for Air Quality Monitoring
I asked the same question in electronics sub, but since it is more general I am asking it here again. I bought the Sharp dust sensor GP2Y1010AU0F. Below are the graph of readings indoor for ~5 minutes,...
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How can I vaporize metals?
What are some common ways that I can vaporize Metals into a vacuum chamber? How can I keep these Metals in a gaseous state?
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How to quantify adulteration of urea and hydrogen per oxide in cow milk? [closed]
I am very much new in this field and trying to get some information on adulteration of cow milk. I have searched and saw that mostly urea and hydrogen per oxide are mixed with cow milk.
I found that ...
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Safely evaporate electrolyte from fragile porous substrate
We have porous ceramic platelets of ~50x5x1 mm³ thickness infiltrated with ammonium nitrate solution (NH4NO3). We want to decompose and evaporate it w/o damaging the fragile substrate (decomposition ...
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Eletrolysis of water
The electrolyser used in the process at 25°C and 10.0 bar exhibits a global yield of 82% with a potential of 1.481 V. Determine the electrical energy that can be electrolyzed by year in order to get ...
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What does it mean by "loops and troughs"? [closed]
Actually, I've asked this question in "English Language & Usage" but someone told me ask it here!
What does it mean by "loops and troughs" in:
"Source has acquired a pattern of loops and troughs."...
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Mass balance of a recycle stream
I'm a chemical engineer student and I have just started to learn about mass balance without reaction.
This is my problem -
I want to find Out the mass composition and mass flowrate of stream Y (...
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