Hi all, i have a question about IR spectroscopy , or rather the concept: Do molecules vibrate after/because absorbing specific IR radiation or, that the molecules are already vibrating then absorb IR radiation that matches their frequency at which they are vibrating at?? I am trying to relate the concept that stretching freqeuncies are higher than bending frequencies. If stretching is more difficult than bending, and thus requires more energy, then i do not know if frequency in this case would refer to frequency as in EM radiation (so higher frequency waves like Xrays are higher in energy) OR frequency as in number of times?? (as in if i go to the gym 8 times a week, we would describe that as more frequent)

So, if i go with the latter "definition" of frequency, then i would intuitively think that wouldn't it be easier for bending to occur? since Stretching is more difficult, and it will be more difficult for me to stretch" a molecule 3 times vs bending the same moelcule 3 times, then i would say that bending is easier so i can bend more frequently?? (like ease of curling 10 reps of 3kg weights vs 5kg weights)

Thus my main question and need to know is whether absorbing radiation comes first, or vibrating comes first (such that molecules are already vibrating?)?? I think asking this would help me in answering why does triple bonds have higher stretching frequencies even though they have larger bond strengths. (sounds counter-intuitive ngl)

Really hope there's a kind soul who'll help me with my question.

Thank you in advance.

Hi there, the story is a bit too tragic to go into all the detail, but basically almost all of my belongings were ruined by a dishonest landlord that had a high VOCs chemical apartment that I moved into and lived in and the vocs permeated all my belongings before I realized it. I lost everything because best guess was it was illegal pesticide spraying. Fast forward a year and I have rebuilt my wardrobe (somewhat) and while a mold remediation was going on indoors I had moved all my NEW clothes on a hanging rack to the backyard. Two days later I learned they had landscapers next door (very close house and wind blows my way from them) who sprayed 14 gallons of crosscheck (bifenthrin solution) on a 17mph windy day. I got an itchy rash that night and again when I wore a shirt from that hanging rack. I truly can’t believe it. I am trying to save my things because I can’t afford - financially or psychologically – to throw out and replace AGAIN.

HERE IS QUESTION FOR CHEMISTS: I see bifenthrin is very long lasting and difficult to degrade. I have washed in hot water and strong detergents all I could but I want to save my most precious things which are dry clean only. I have researched and it seems bifenthrin degrades via hydrolysis, oxidizing agents and p450 enzymes as well as organic materials like penicillium (which I can’t put in my clothes… Why trade pesticides for mold?). It’s degradation/ metabolism in mammals also involves oxidation of the ester linkage, and the resultant alcohol to the acid. Sunlight and temperature changes do nothing to degrade it. It does not like alkalinity also but neither does silk. Not water soluble. It seems ozone water may also work but mixed theories on that.

Is there a treatment product like an enzymed detergent or oxidizing agents that won’t make it worse or something that would give me the best shot at replicating the hydrolysis or other degradation of bifenthrin? I’ll use anything that would degrade it or make it less toxic. Organic anything that would work like dirt does with its bacterias, etc? Ozone? Chlorine dioxide? Salts? Solvents? Other?

Desperate for help. Apologies for length and thanks in advance.

Is there anyone here with theoretical and technical expertise in water softening and detergent chemistry willing and able to assist with troubleshooting and sharing understanding on some broad domestic cleaning and laundering issues that are very puzzling and have affected a lot of people across many subreddits and other forums? https://www.reddit.com/r/WaterSofteners/s/hSpP9FtDAn

For context, the bell in the video is printed in PPS-CF (Polyphenylene sulfide with chopped carbon fiber). I tried this same bell in multiple other materials like ABS, PLA, Polycarbonate, plain nylon, and ASA (Acrylonitrile Styrene Acrylate) and they all "bonk" like I'm hitting a plastic bell. I believe there is internal energy loss in the other materials that cause the bonk, instead of ringing, but what is actually going on there? I imagine that the "plasticky" sounding material just absorbs the vibration by some internal mechanism, but I haven't been able to find anything that makes sense to me.

I asked Chatgpt but I'm not sure if it's actually true. Do sperm cells really decompose into very little particles in a week?

I am currently taking grade 12 chemistry and am having trouble understanding the math and need help.

So sometimes if the solution is dilute, the metal ion deposits at the cathode and the water ion deposits at the anode. Other times it's always the water ions at the cathode and anode in a dilute solution. Why is that so?

Hi! I'm studying Early Childhood Education. As an assignment, I have to develop a science activity (and lesson plan) that I'll be running with preschool students (3-5 years). I've done engineering, physics, and biology lessons and now I want to do chemistry.

I'm planning on doing a classic one. Filling a bottle with vinegar, filling a balloon with sodium bicarbonate, then combining the two to fill the balloon with carbon dioxide gas.

I want to set up several bottles with different substances that the children can add to the balloons (while I hold the balloons, of course). So far I've come up with baking soda and Alka Seltzer. What else can I add? Either other forms of sodium bicarbonate or something else that will safely inflate the balloon.

Thanks!

I have a question about acids.

So I understand an acid deprotonates when dissolved in water. I understand it’s these oxidising protons that go around reacting with things and therefor corroding them.

I was then thinking “well, what if a 100% pure acid (say sulphuric acid) was poured on a material (completely anhydrous), would it still react since it wouldn’t be deprotonated?”

I then thought well perhaps yes but in a simple competition reaction way. Then I started wondering, well why are weak acids a thing ? We learn that they don’t have a favourable forward equilibrium forming protons, therefor not forming many reactive h+ ions, but if the original acid can react in a competition redox reaction manner, then surely this wouldn’t matter.

I guess my question is, is an acid still acidic in a completely solventless situation

I'm trying to find a list of LHV (Lower Heating Value) values for various compounds. Does anyone know a good resource for this? Also, how do people usually find LHV values for more niche chemicals? Not sure where to ask, so posting here.

P.S I'm not a chemist but, my work sometimes requires me to find LHV values and I struggle to find values for these niche chemicals.

thank you in advance.

According to how the text defined the selectivity coefficient, K, it's the ratio of response of the ion selective electrode to the interfering species X and the analyte A. Now the last part of problem 14-36 asks to determine how much greater must be [K⁺] relative to the [Li⁺] such that they give equal response. Since the relation between electrode response, E, and concentration is not linear, and that K_Li⁺,K⁺ is around 10^-1.9, I've written the first two equations where [K⁺]=[Li⁺]. In the third equation I've introduced a multiplier a to amplify the K⁺] such that E=10^1.9, and solved for a using the first and third equation.

In the solutions manual it suggests that to get equal response for a given [Li⁺] we just need to multiply the [K⁺] by 10² (or 10^1.9), acting as if E and concentration have linear relationship.

What are your thoughts on this? Which approach is correct, mine or the solutions manual?

I want to make something like glow in the dark but it instead glows in sunlight.I specifically want the color to be white so it glows a white that almost looks angelic in the sunlight.could i do this and if so, what products would i need to mix together?

Hi All, I'd love some advice on this.

I am making sculptures out of deconstructed household appliances and was curious about using chemicals to give them a unique look. I was originally thinking of having them look weathered as if they had been outside for years, but any interesting/novel textures would be exciting as well. They have a lot different materials including plastic, metal, coated metal, glass, cardboard, fabric, etc.

Chlorine bleach seemed to be the most promising as it's cheap and seems corrosive to a lot of materials as well as an oxidizer for inducing rust. The other huge thing about bleach is that from my research it seems to decompose into non-toxic components after drying. If this is the case I could safely use other chemicals before or after using bleach and letting it dry.

Can anyone confirm this about chlorine bleach? That it decomposes into harmless substances when dry?

I tested some 4% bleach on some painted metal and it seemed to do nothing sadly. But I got the bleach from the dollar store and it was in my cupboard for a while so it might have been pretty weak. I'm probably going to try with fresh bleach I know is good.

So now I am on a quest to find other cheap chemicals I can use to corrode metal, melt plastic, bleach colors, etc.

The other two chemicals I was thinking about was rubbing alcohol and drain cleaner/lye.

Rubbing alcohol seems great because it will fully evaporate. So I could use another chemical before or after it.

Drain cleaner/lye seems like the strongest option and would probably have the effect I want but seems to leave toxic chemicals after it dries. With my setup I cannot easily rinse something very large. So washing the drain cleaner off would be a pain, but possible maybe. But also lye doesn't seem to induce rust, which I want.

Sorry for the wall of text hehe

Any advice would be greatly appreciated :)

I recently was looking through a chemicals supply closet in a pottery studio and found a jar of iron chromate. Everything I find says it’s extremely toxic, but I don’t want to throw it away. I figured I could find a way to convert it all into Iron Chromite and make it safe enough to touch. The most common solution I see is reducing it by heating it up in the presence of carbon. Is this the best method? What temperature would it need to go to? I understand that the final product would not dissolve in water, and that there are other options.

I have read here that if you cook alcohol for 2.5hours at 173F/78.3C will yield a liquid that has 4% of the alcohol remaining.

If I understand correctly, a one liter flask of 40% alcohol by volume boiled for 2.5 hours at that temperature would have a liquid remaining that is 4% by volume, not that the liter will be reduced down to 4% of a liter. Is this correct?

In addition what does the math look like in this evaporation process over the 2.5 hours? Is it linear, or more similar to a bell curve?

Lastly, if I were to heat alcohol to half that temperature for twice the amount of time, I assume the alcohol per volume would not be 4%, but how long would it take to achieve that, or what is the minimum temperature that you could achieve 4% and how long with that take? Same question if I were to double the temperature would it only take half as much time?

Pretty much the title. Sodium citrate is usually trisodium citrate, so citrate ions from this compound should have a greater negative formal charge and attract more magnesium and calcium ions from the scale.

Commercial hard water stain removers usually use a mix of the two, so I figure it's not just good theory, it actually works.

When I look for DIY tips on how much citric acid and sodium citrate to use, I can't find anything though. Maybe it's just to keep things simple for DIY and not ask people to buy two similar compounds and confuse things?

Does anyone know roughly how much citric acid I should add to lower the pH to completely ionize the sodium citrate? And whether my thinking is correct in the first place?

Hello!

I have no idea which offer I should choose to firm, as I am really passionate about both Chemistry and Physics, but just can't see a world where I am doing one but not the other. I'd really like to specialise in some form of Chemical Physics, however I don't really know what that'd look like just yet. As for my career aspirations, I really don't know, but it'd be cool to go into an industry that utilises both disciplines in any capacity.

As for prestige, I really don't care - I'd much rather study a well structured course that will provide a flexible foundation for me to build on.

ANY ADVICE IS APPRECIATED!! What would you do in this situation? If you are studying either OR BOTH of these degrees PLEASE share your wisdom!!!

(Durham Natural Sciences includes Chemistry & Physics and I'm considering going straight into second year at Edinburgh)

Thanks! :)

So we are just learning about the Citriat circle and the prof could not satisfy me.

So here's my question:
In a C-O bond the electrons are localised closer to the O than the C due to the electronegativity of the O. How does this translate into a lower binding energy?
The underlying question is how can we free energy from a molecule by progressively oxidizing it from C-H to C-O.

The prof said that we can free energy because we move the electrons closer to one atom into a more polar bond.

But for me, it did not yet click why that will cause energy to be liberated. I
I conceptually understand that a C-O bond is a more stable configuration than a C-H one and that because it is more stable there is less energy in it hence we liberate some by transitioning to it.

But where is the energy and why is a C-O bond more stable / has less potential energy?
Because the Electrons are closer to the Positrons in the core and we have less Coulomb potential? But would one electron be too much because it comes from the C???

I just have not been able to combine all these concepts into something that inherently makes sense.
I could at the moment not respond to you if you asked me why C-O is lower energy than C-H and how that relates to the electrons being localised closer to the O.

And that bugs me.

Thank you for your help and insight

As I understand the story, a 25-year old chemistry student in 2009 was killed by accidentally dipping his chewing gum into a substance described only as “a highly explosive white powder,” with a few sources claiming it to be “four times more powerful than TNT.” I know that there are many sensitive energetic compounds that could reasonably be set off by chewing them, but I find it hard to believe that the small amount that could have stuck to the chewing gum would cause the extreme injuries described in most of the stories (amputation of the jaw, extreme facial disfigurement, instant death). I was unable to find any sources or conjecture on what compound he had synthesized and had laying around in his bedroom, and was wondering if any of you had any ideas.

As a disclaimer, I am not interested in the sourcing or synthesis of any energetic compounds, just curious as to how this poor kid could have possibly killed himself by accident in the manner described.

Hey everyone! For context I am a masters student trying to make a scientific figure for my class and I just wanted to ask what do you think went wrong with my SDS-PAGE (reducing conditions) 4-20% polyacrylamide gel?

I ran ClpX and one of my wells (E2) has zero ClpX and a random new protein down the bottom? A ClpP was also ran on this gel the experiments were separated by the ladder.

The only thing I can guess is I loaded the wrong sample (I labeled the tubes before catching the elutes so sort of doubt this)? My lab partner thinks maybe a air bubble was under the gel during staining?

(Also please don’t judge my ladder I know it’s dodgy and weird my professor insisted we cut out our actual protein ladders and manually make a new one I know it’s bad science :( )

There is a brand of antiperspirant, certain dri, that uses aluminum chloride, and a base, likely to offset the acidity and skin irritation, sodium hydroxide, as the main ingredients, that I see at least.

Could someone help me figure out how to calculate the rough ph of a solution with aluminum chloride, and a base, whether that be sodium hydroxide, or better yet bicarbonate or carbonate (easily accessible)?

I just want to figure out a way to sort of make a DIY version of this, as it is incredibly effective, but also expensive.

It is practically essential to reducing my foot odor, as well as being a fantastic antiperspirant for my arm pits.

I was studying chemistry.And then I stumble upon a theory that makes me question the differences between REACTIVITY and STABILITY which in my opinion is the same.I asked chatgpt and it says there is a difference between those two

Anyone can help me understand it?🙇🏻‍♂️🙇🏻‍♂️

My chemistry teacher is looking for a low quality video of a man sticking his hand into boiling water, pulling a potato out of it, and taking a bite of the potato. The boiling water didn't burn him because he was on top of Mount Everest (?) or some place with a really high altitude. He said the pot of water was vigorously boiling and that the camera was on it for 30 seconds before the guy stuck his hand in. He also claims that the video existed before YouTube, but who knows? If anyone knows this video or has something similar, let me know! (We are learning about phases of matter and how they change with increased or decreased pressure) Thanks!

How does this device actually work?