/r/chemistry

Photograph via snooOG

A community for chemists and those who love chemistry

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Notes:

  • If you're looking for a more concentrated, advanced discussion of chemistry topics among professionals and grad students, check out /r/Chempros.

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Past Weekly Topics

/r/chemistry

2,392,585 Subscribers

1

Studying Tips Analytical Chemistry

Hi everyone! I am a US international student studying in Europe and I am taking an Analytical Chemistry course while I am here. I recently changed my major to chemistry and don’t have a lot of experience and I was curious if anyone could mention what worked for them when they studied analytical chemistry. The final exam for the course is an oral exam. Anything helps, thank you!

0 Comments
2024/02/12
10:46 UTC

2

Labster

Hi!

So despite having 6 hours of lab every week, I’m required to do labster simulations.

I have a pretty good laptop (literally runs games like last of us and hogwarts legacy fine) but every time I attempt to use labster, the lag is just insane. Anyone know why this is?

My old macbook seems to run it smoother which is insane.

0 Comments
2024/02/12
09:46 UTC

1

Dyeing Using Plant Extracts

Hello. Would like to ask for recommendations for simple protocols for plant extraction and dyeing. Thank you.

0 Comments
2024/02/12
09:14 UTC

1

Asking about pH of water

I found two diffent kind of bottled water listed with different pH. The first has a pH of 8.3, but has a far lower mineral content, the second is listed at 8.1 pH but it has more bicarbonates, calcium, etc. Why the first one has a higher pH since it has far less (half) bicarbonates? An higher pH should better neutralize pepsin, but how can be that if it has almost no mineral content? Are both alkaline?

Thank you

2 Comments
2024/02/12
09:01 UTC

3

For all my chemists! Whats your typical job day look like?

Be as honest as you possibly can…I ask this as I am a high school student (Australia!) who is considering a career in chemistry! Specifically nuclear chemistry…i like that :)

Though the field in itself seems all so ambiguous when it comes to what you actually work on in a typical day. It all seems so vague that it's actually quite nerve wracking…everyone appears to know what they are doing, while I feel I barely remember what I learnt last term. Haha!

In that respect, it's intimidating. But I feel it would be good to actually see if it's as spooky as I imagine it to be…best to know what I'm getting into!

Thank you for your time!

11 Comments
2024/02/12
08:03 UTC

1

Have any of you worked with di-n-butylmagnesium?

https://preview.redd.it/nj6nx64d14ic1.jpg?width=1024&format=pjpg&auto=webp&s=67e5b30b2b3ab394dad39edf9ad2bd1dc72d227a

I'm cleaning out old chemicals and found this little darling.

Whoever used it is not around anymore.

Since it has the old style of label, it is for sure more than 10 years old, and anybody needing it would order a new rather than use this one. It has to go.

Two things makes me wonder

- The SDS only says it is flammable, not pyrophoric. But a am quite prejudiced towards organoaluminum and organomagnesium compounds.

- The SDS also says "releases toxic gas on contact with water". Could that be something else than CO?

The bottle is closed with a plastic lid and a (quite molested) "sure-seal" cap.

10-20 mL remain.

I'll draw a small sample out and see how reactive it is. If it can be handled, I guess burning it a few mL at a time is the easiest disposal.

https://preview.redd.it/90kpc0lg14ic1.jpg?width=1024&format=pjpg&auto=webp&s=5f7db14a14f7a7323133ff71ab926cd2658201de

https://preview.redd.it/eyje93nk04ic1.png?width=1610&format=png&auto=webp&s=0aa312818f69117382c33179a10241403d4cfb7f

3 Comments
2024/02/12
07:59 UTC

1

Simple Way of Extracting Oxalic Acid from Cucumber Peels

Hi! Does anyone know how to extract oxalic acid from cucumber peels without any complicated procedures? We badly need to know in order to procede with our Experiment. Thanks!

2 Comments
2024/02/12
07:28 UTC

2

Foundations of chemistry

Just saw that for most physicist they need to form a good foundation in classical,statistical , and quantum mechanics to form their base in undergrad. I was wondering what would form the foundations for a good chemist. In my opinion chemical bonding, chemical thermodynamics, acid base reaction , reaction mechanism etc seem pretty important

1 Comment
2024/02/12
07:16 UTC

22

I added all the Periodic Table elements to the IndexFlip study site

3 Comments
2024/02/12
04:40 UTC

1

Could anyone recommend a good chemistry experiment that’s able to be graphed

My science cba (classroom based assessment) is coming up and I need to make an experiment that I can graph the results of against something else like if I do this thing the result changes by this much but if I do this is changes by this much kind of thing so could any recommend any good chemistry based ones

7 Comments
2024/02/12
03:38 UTC

77

Quantum Chemistry is kicking my ass

Just got a 40 on our first exam, worth a lot of our grade, with a professor who doesn’t curve.

For those of y’all who had to suffer through it, how did y’all pass? How did you survive? Is there any hope for my lowly grade?

I’ve heard that Physical Chemistry was a monster all of my undergrad, but I had no idea it was THIS bad

33 Comments
2024/02/12
03:38 UTC

0

How do would you transfer cesium from an ampoule to a closed system without causing oxidation?

Say you have a highly reactive element like cesium in an ampoule. How would you go about transferring the cesium to a closed system while avoiding impurities and oxidation? If samples come in ampoules isnt there a safe simple way of getting said sample of the element or compound into a closed system for experimentation without causing exposure to open air. Note this is not a break seal ampoule i am asking about this is just a standard ampoule. Any systems or methods feel free to mention. *Warnings and general pessimism and negativity will be ignored as it adds nothing of interest to said question.

8 Comments
2024/02/12
02:35 UTC

4

Tips for GC injection?

Been practicing using a GC these past couple of weeks as I’m starting a research project soon that will require it. I’ve been injecting 1 microliter of 1:10 v:v Grob mix with the goal of peak areas agreeing to 5% or better. For some reason I’m having a lot of difficulty getting it right, my peak areas are usually 6-10% off from each other. Any advice?

5 Comments
2024/02/12
01:22 UTC

0

wanna make own care products... any idea where to begin?

am trying to learn sopanification and i need:

1 fluoride
2 baking soda
3 potassium hydroxide (lye)
4 sodium hydroxide (lye)
5 xyloitol for tooth powder

any idea where to get these from a reliable seller?

am sick and tired of quality control worrying and product research and cost n quantity and a ton of other shit.... fillers and preservatives and fraagrances and flavors and sulfates blah blahb lah list is on....need to make own tooth powder and own soaps, any idea where to start?

need to know reputable / how to spot reputable chemical companies with reasonable prices... is there a specific sub for chemicals, or?

54 Comments
2024/02/11
23:42 UTC

0

Making magnesium chloride from Magnesium and Hydrochloric Acid (HCl)

0 Comments
2024/02/11
23:40 UTC

3

Crystallization VS Precipitation

I did some research on the topics of crystallization and precipitation for my chemistry assignment, but I was confused about the differences between the two. I know that crystallization is a process where the unit cells are organized into a building-block sort of structure, creating shiny and smooth surfaces of the crystal, whereas precipitates would usually be more powdery (?). So, then, would an example of a precipitate be something like salt?

My friend wrote something like this for her borax-crystal assignment: "This change is classified as crystallization due to the change only ever being physical. Since the borax was combined with the water it produced uniform shapes and did not produce new compounds, so this would not be classified as precipitation but rather crystallization." Would this be correct, since no new compounds can be made in the process of precipitation? Or are compounds made during both processes?

Additionally, are precipitation and crystallization physical or chemical changes? How would you know if the product of an experiment is the result of crystallization or precipitation?

Sorry, I just have a lot of questions...

9 Comments
2024/02/11
21:54 UTC

110

Want to do an organic chemistry PhD but hate columns

Anyone else hate columns but got through an organic PhD anyway?

Ive been working in process chem for the last few years in industry and i did a column maybe once every couple of months and that was using a biotage so I could put it on and walk away. I can do them, theyre just so boring and tedious. And a PhD will basically be 5-10 columns a week for several years. I am enthusiastic about everything else (in terms of leading your own project, thinking of new experiments, going through NMR data, presenting data, etc) but the thought of doing columns every day for the next few years is off-putting.

69 Comments
2024/02/11
20:48 UTC

0

Does k also encompass the number of places molecules could meet in rate equation?

In the equation rate=-k[x]^n I understand that your concentration to the nth accounts for the likelihood of two particles being at the same place at any given time. If the likelihood of one particle being at a specific place is just it’s concentration (number of particles over how many places are available) and the likelihood of another particle being at the same place is the same, you multiply them to know the likelihood of them being at the same place. K takes into account the likelihood of reaction upon their meeting. Wouldn’t k also have to take into account the fact that there is also a certain number of places that those molecules could possible meet? If I’m understanding it, multiplying the two concentrations gives there likelihood of meeting at one specific place, so does k take into account that there are many certain places that they could meet?

9 Comments
2024/02/11
20:16 UTC

5

Lab SOPs

Hi, does anyone know a good repository for basic laboratory SOPs online? I need to write a bunch from scratch but it would be a huge time saving if I could tweak existing ones rather having to create them entirely. Thanks!

2 Comments
2024/02/11
19:06 UTC

0

How can I manually break down Glyoclipids in cider?

I bought some cider to convert to hard cider. However, the yeast is not kicking off like it should. I then realized that glycolipids were added to the cider to deter bacteria and yeast.

I'm looking fro a way to remove or destroy the glycolipids without ruining the cider itself. It seems like glyciolipids break down in to a sugar and glycerin, which are human safe. Resources online tend to talk about what humans can take to help with our natural processes to speed up fat absorption. This is not what I need.

I've performed some basic research and it looks like gut bile type acids could help:

- https://en.wikipedia.org/wiki/Ursodoxicoltaurine - Helps "absorb" fatty acids, but it looks like that doesn't break them down, it just helps them mix with water easier.

- https://en.wikipedia.org/wiki/Deoxycholic_acid - Is used to break down fat in cosmetics via injection, but doesn't look like it's available.

So yeah, does anyone know what I can add to my cider to break down the glycolipids that remains safe and non-gross tasting?

7 Comments
2024/02/11
18:49 UTC

1

Cleaning out substances in antique bottles

I bought a bunch of uncleaned, antique bottles in South Dakota United States. They were dug up from an old ghost town. A lot of them were closed (not sealed but closed with a cork) and had substances in them. Some have writing on them and some do not.

A lot of those substances are clear but when activated by water are turning different colors.

One I opened and it had a very strong metallic/acetone smell. It filled my entire house. I've washed my hands multiple times and it still hasn't come off. I licked my finger (after washing my hands three times. Once with vingear, an exfoliating scrub and another with my normal soap) and it made my tongue feel weird, still does a little bit. It also still smells as strong on my hands as it did the first time. In hindsight I should have worn gloves. It's a glass, amber Lysol bottle. Likely hasn't been opened in a while. It's definitely made my head and stomach feel a certain type of way.

Currently airing out my house now and hoping it goes away.

How do you go about cleaning out old bottles/unknown substances? Historically the contents could be anything from colored water to cocaine. Or anything in-between. Considering the time period. I typically use Orvus paste but my sister brought up a good point that I'm not sure what I'm activating in some of these bottles so maybe something not so caustic? Dawn seems to not be moving any of the debris/old contents.

2 Comments
2024/02/11
18:34 UTC

0

Calcium Oxalate Reactions

Hi! I'm an amateur chemist currently working on an independent chemistry project involving several calcium compounds. I was curious about calcium oxalate in particular, as I found a lot of conflicting research on it. For example, I ran into some research stating that it reacts with acids like hydrochloric acid, sulfuric acid, and nitric acid. Unfortunately, I lack the knowledge to be able to ascertain whether or not these reactions make sense in the context, and I have a lab proposal submission coming up. Any help on whether they happen or not would be really appreciated, as well as any additional reactions (other than conversion to calcium carbonate). Also, an explanation of the logic of the reaction would be great. Finally (and this is completely out of my realm of knowledge), is something like electrolysis also feasible in a lab?

5 Comments
2024/02/11
18:31 UTC

4

Au from 14k gold

Could i get almost pure Au metal from a 14k Au alloy? I tought of dissolving the gold in HCl and H2O2 solution then adding something like potassium metabisulfite to precipitate it from chloroauric acid but im afraid that other metals that have been dissolved like Cu (into CuCl2) and Ag (into AgCl) or other metals will also crash out. I dont see any useful info on youtube and google doesnt help. Any suggestions? (I have some jewelry made of 14k gold and thats what i want to refine)

4 Comments
2024/02/11
18:27 UTC

0

Questions about PFAS, lead, other chemicals…

I had a bunch of clothes from SHEIN that I bought a while ago (I don’t buy from them anymore) but I read that they contained dangerously high levels of PFAS, lead, and other chemicals. I soaked them in my bathtub to try to remove them (before eventually getting rid of all of them) but the water from soaking them spilled all over my floors when removing them from soaking. Did the chemicals transfer from the clothes to my floor and are now being transferred all over the house? (Laminate and carpet floors) if so, what’s the best way to try to remove them?

Thanks in advance!

3 Comments
2024/02/11
17:26 UTC

2

Self studying chemistry - where do I start?

I already have a BA and an MA but in the humanities. I’ve always loved chemistry — and STEM in general.

I’d love to start studying chemistry by myself but I’m not sure where to start. Any tips? (I’ve already taken chemistry at school so I’m familiar with some of the basic concepts).

3 Comments
2024/02/11
17:10 UTC

747

No safety goggles or lab coat. Lewis doing some stupid moves lately.

88 Comments
2024/02/11
15:46 UTC

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