Glenn T. Seaborg Signed Periodic Table
https://redd.it/1m640ur
@r_chemistry
How does your lab handle microbial contamination checks — CFU counting?
For those of you working in labs where microbial contamination matters (e.g., pharma, food, water testing): How do you handle CFU counting?
Do you rely on manual colony counts, or is there an automated/digital solution you trust?
Trying to understand what practices are most common when microbial presence matters in a chemical or cross-disciplinary setting.
#
https://redd.it/1m5r9yt
@r_chemistry
What’s working QC like?
I’ll be graduating this fall with a BS in Chemistry and am thinking about what’s next. I like chemistry, but also love to write and draw, and might like to try make a career out of it.
If I were to find a QC job, what kind of downtime would there be to do these things? My dream scenario would be sample prep in the morning, and then sitting with instruments and drawing or writing in the afternoon. Is this a realistic hope, or are QC jobs just work work work the whole day?
Thanks.
https://redd.it/1m5r1dz
@r_chemistry
Widespread misidentification of scanning electron microscope instruments in the peer-reviewed materials science and engineering literature | Thousands of materials science papers misidentify the scanning electron microscope used among other issues, hinting at the involvement of research paper mills.
https://doi.org/10.1371/journal.pone.0326754
https://redd.it/1m5rjwu
@r_chemistry
The Burn-Reverse Paradox
if we burn a log of a wood, and like reduce it to smoke and ash. and somehow managed to collect its every molecule and then also make it arrange and reassemble it exactly-
Did the fire still happen?
if chemistry is reversible in theory but irreversible in experience
Where does the event go? Is chemistry only a reaction -- or also a record?
This is a paradox about which I read recently, and I thought it would be good to discuss about other people's point of view in it and trying on getting a better perspective on its philosophy.
https://preview.redd.it/cgq5cxfxl9ef1.jpg?width=678&format=pjpg&auto=webp&s=685b96d0878bc40317b5716730202fd733f061c6
https://redd.it/1m5ppcc
@r_chemistry
Alibaba lab equipment
It's so cheap it's hard not to be tempted! Has anyone bought lab equipment from Alibaba et-al? Turbine mixers, shear mixers.... flash point tester? We have a manual closed cup tester that we've used for years - but it's time consuming and sometimes techs misread it, but Alibaba et-al have automatic testers for a couple grand USD. Hard to pass up, and we can always verify questionable results with our old school machine I guess....
Anyone play with this stuff? We're not a F500 company, a Koehler or Anton-paar tester isn't going to happen lol. We also don't need to submit data for ASTM standards etc, this is for internal knowledge, SDS generation, etc.
https://www.alibaba.com/product-detail/Petroleum-Products-Analysis-Equipment-ASTM-D93_1601232292881.html?spm=a2700.details.you_may_like.1.b107191bsuvDwq
https://redd.it/1m5n0hq
@r_chemistry
I Love Organic Chemistry So Much!
Yall I love organic reactions so much😔. I'm starting my PhD next month and they told us to just refresh our memories over undergrad concepts in our field and I'm so happy working through the organic mechanisms! I'm just watching The Organic Chemistry Tutor's short videos on the concepts, nothing too crazy because I still wanted to rest😂. Going back over these reactions now without the pressure of an exam makes it so much more fun and I feel like I have a much better understanding of the science behind the reactions/mechanisms. For instance, when we were being taught about Markovnikov and Anti-Markovnikov the first time, I couldnt really understand how to know which reactions would be Markovnikov and which would be Anti. But NOW??? It makes SOOO much more sense!
Instead of trying to memorize, I look at a mechanism and I can just tell. I know this reddit is filled with experts lol😂 so my apologies if it's like "Duh!" but I truly loved my org. chem classes and wanted to be like the grad students, professors, etc. who, in my eyes, could just look at a random reaction (whether it be a textbook one or otherwise) and know exactly which mechanisms to draw out, predict side products really well, etc. It just made me happy and made me feel like I was getting closer to that point. That's all!
https://redd.it/1m5jtdl
@r_chemistry
UK - Edinburgh grads worse off than reading grads?
Was looking at some LEO data, and Edinburgh chemistry grads make slightly less money after 5 years than reading grads( ~£35k).
In fact, reading grads make more / the same as Queens mary, Birmingham, York, and Warwick grads.
Kind of crazy. It seems that University prestige doesn't matter that much in chemistry.
Also, Hull chemistry grads (who's department no longer exists) have better salary outcomes than York chemistry students lol
https://redd.it/1m5fzci
@r_chemistry
When calculating weight percentage, should I consider density in a solution?
Hello everyone, I’m trying to learn analytical chemistry by my own, and I got the question but ChatGPT doesn’t answer it.
I wanted to calculate a weight percentage of a solution, I know how much ml of concentrate there is to how much water (1 liter total solution volume)
So I ended up with 2 ways of measuring, in the first one I divided the mass of a solute by just 1000g. And in the second one I considered density of a solute (it’s lower than water) and my mass of solution was 999,4g instead of 1000g.
Which one is the right way? For me it seems like second guess was right
I’m sorry if I write my thought badly, I try my best
https://redd.it/1m5ehu8
@r_chemistry
Bro what I even is this? 😭
https://redd.it/1m590p3
@r_chemistry
Steel + Hydrochloric acid
I am removing galvanizing from the steel mesh with diluted hydrochloric acid, and since I didn't have container big enough to fit it, I had to dip the mesh half-way dip it two times, exposing one side to the air, while being covered in the acid.
After that I neutralized acid (and possibly removed remaining zinc) by dipping the meshes into NaOH solution, and I noticed that half of the meshes are covered with something brown that looks like rust. But unlike rust, it was somewhat easy to remove it with soapy water. What is it? Some sort of ferric chloride, or just rust that didn't completely lock onto the steel?
Also, what would be the best way to prevent rust formation until it gets painted (paint I want to use is incompatible with zinc, so I had to strip it off)?
https://redd.it/1m52mi9
@r_chemistry
How can I remove the lithium from these batteries or dispose of them safely?
https://redd.it/1m51fpz
@r_chemistry
Methylorange all over the place
https://redd.it/1m4zq8e
@r_chemistry
On the Origins of Life: Recreating Cellular Metabolism
https://today.ucsd.edu/story/origins-of-life-cellular-metabolism
https://redd.it/1m4wrvb
@r_chemistry
iron perfume
i searched out what gives of the metallic smell on your hand after you touch iron and they say its FeOH reacting with fats on your skin making long chain iron carboxylates ,
so i want to try basic hydrolysis of an oil using FeOH as the base
and see if it would smell like your hand after touching iron
https://redd.it/1m4mr1g
@r_chemistry
I dropped 5.2g of clean and dry product in my RBF
https://redd.it/1m60bbx
@r_chemistry
Is my goal realistic?
I enrolled and got accepted to the bachelor's program for food technologies.
The thing is, I don't know anything about chemistry and my math skills aren't that good either. I've been learning maths on my own and it's going great so far. I've been studying chemistry too but I've spent less time on it than maths. I'm not really sure what to expect from the program because I never really had good grades in chemistry, so I'm wondering if I can learn enough until the first semester starts (October), or should I just not waste my time and switch to something else? I browsed this subreddit and found some book suggestions, and I have some other sources, too.
I have the time to study, I want to study, I just don't know if it's realistic to learn high school level chemistry in about 2 months. Any advuce would be appreciated, thank you.
https://redd.it/1m5yqso
@r_chemistry
Is the ammonia and bleach at my place of work mixing to produce chloramine?
Hi, I work on an insect farm and was hoping for some chemistry insight. There's generally some ammonia in the air, an average day would be 0 - 5ppm but can be 20+ppm. We have a reader to monitor it but you can generally tell when it's 10+ppm as soon as you walk in.
We also regularly use bleach on the floors with a mop and on work equipment in the washing machine to prevent a build up of bacteria.
Is the ammonia in the air and bleach on the floors/equipment combining into low levels of Chloramine and poisoning us?
https://redd.it/1m5vffl
@r_chemistry
Rose Bengal and Filming Amines
Hi,
I don't have a strong foundation in organic chemistry, so I wanted to ask for sort of an ELI5 explanation. I'm trying to understand Rose Bengal (a dye used in biological stains) and how it reacts with a class of amines called film forming amines like Octadecylamine (ODA). These amines are apparently used in boilers to protect against corrosion. I think the idea is that they are fed into the system as some kind of a proprietary formula and then tested at the return to see how much is adsorbed into the system.
I tried scouring online, but I have not found anything that can simplify or explain how this mechanism works. Rose Bengal is referred as a Xanthene dye, an anionic dye and it reacts with film forming amines like octadecylamine and then an acidifier is added to bring the pH down to between 2.3 and 3.3. Here is a patent I found: https://patentimages.storage.googleapis.com/b9/01/81/6e6e75ec10231d/US9588090.pdf
I have used this test before and it seems like a finnicky test, very poor repeatability.
A couple of questions I had was:
1. If the dye is anionic (perhaps a sodium salt), how does it really react with ODA? What sort of reaction is taking place? Is it a reaction between amines and carboxylate?
2. What is the basis behind bringing the pH down to 2.3 - 3.3 for the reaction to work? Just adding the dye to the filming amine sample makes it pink, and after I drop the pH, it seems to be less intense. Why?
3. Would the order matter (dye first or acid first)? I seem to notice that sometimes the dye precipitates out into suspended particles.
If someone has experience in this type of testing, please talk to me. Thank you!
https://redd.it/1m5s3iz
@r_chemistry
Hi guys can somebody tell me on which ocassions to use those equipment?
https://redd.it/1m5po4r
@r_chemistry
Salt to calibrate hygrometer
https://redd.it/1m5i7pw
@r_chemistry
Can someone help me with this question please? Most people say it's B but some have said it's A and C.
https://redd.it/1m5jgmb
@r_chemistry
Weekly Careers/Education Questions Thread
This is a dedicated weekly thread for you to seek and provide advice concerning education and careers in chemistry.
If you need to make an important decision regarding your future or want to know what your options, then this is the place to leave a comment.
If you see similar topics in r/chemistry, please politely inform them of this weekly feature.
https://redd.it/1m5fvgn
@r_chemistry
Chemicals in fragrances
Hi, I post this in another sub but a person recommended me to post in here to get a more educated answer, the question was:
Are you not concern on the chemicals in fragrances(perfumes)? I was reading a few things about it, but not sure if anyone ever experienced some problem or know someone who did
https://redd.it/1m5905c
@r_chemistry
Moss disposal after absorbing heavy metals or toxins
I googled about research into using moss to absorb toxic chemicals or heavy metals and I don’t see much. However my husband says my google abilities suck so maybe it’s me.
BUT I want yall’s opinion on how to safely dispose of moss after it’s absorbed something you don’t want to burn back into the air.
https://redd.it/1m572f2
@r_chemistry
Stuff that looks like snow
So me and my friends went to this abandoned building and found a pile of snow mind you its the middle of summer. My friend grabbed that snow and rubbed it on my other friends arm despite his protests and they both started itching really badly, also we were drawing on the walls with acrylic markers and my friend wanted to rub that "snow" where I wrote with marker and the snow started burning the marker, when we found a fountain and washed it off it didn't burn or anything. Could anyone tell me what that snow actually was? I tried looking it up but nothing matched what it actually was.
https://redd.it/1m52ynl
@r_chemistry
What's the most interesting thing that you've learned in chemistry class?
https://redd.it/1m4y95t
@r_chemistry
Spoon material identification
https://redd.it/1m4wha6
@r_chemistry
Issue with data cleaning, can anyone please help?
We have 50 minutes of gas data using FTIR. And, we have 50 minutes of data in full. We are only interested in the last 20 minutes, not the first 30 minutes and this is the background that we want to remove when we make calculation. Even further, some of the numbers are below zero. We don't want to take them into account when calculating area under the curve. How do we do that?
https://redd.it/1m4sfh6
@r_chemistry
High concentration of Xylene measured in bathroom
We have bought a newly built house and have been living in it for a year already. Since the beginning we have been smelling an intense chemical smell in the bathroom whenever we would close the door for longer period of time. This bathroom does not have any window, only has bathroom fan. Last month we have decided to do air quality test and the test came back with elevated concentration of Xylene (293 µg/m3) Would anyone have any idea what could be the source? Could it be still the material itself even when we have been living there already for a year?
Any advice would be appreciated, we really have no idea what could be causing it and how could we solve this issue…
https://redd.it/1m4lu3o
@r_chemistry
