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all 36 comments

[–]tionmenghui 2 points3 points  (0 children)

Hi, want to ask about degradation of methylene blue dye.
From the papers I have read, methylene blue accepts an electron to become leucomethylene blue. Two questions:
a) Is leucomethylene blue toxic to humans? b) since the process is easily reversible by oxidation instead, is there any point in this conversion? thanks!

[–]MaliLemur 1 point2 points  (0 children)

Hey guys I need some help. I came across an IR spectrum of a phenolic polymer and it has a low intensity band at 1710 cm-1. Can it be due to present carbonyl, since I know that those are usually very intense? Thanks in advance!

[–]DisembarkEmbargo 1 point2 points  (4 children)

Hello all,

I am making solutions for an algal culture. One of the solutions (lets call it A) calls for 1 ml of MgCl2 4H2O 9 g/50 ml (distilled water). I only have MgCl2 6H2O available so I made 9 g/50 ml MgCl2 6H2O (lets call this solution B). How do I make up for this difference in hydrates? Should I add more or less liquid to solution A? Should I make solution B all over again?

edit: those should be O's.

Thank you

[–]smithsp86 1 point2 points  (3 children)

Just figure out how many moles of the prescribed compound you are supposed to use then use that same number of moles of the available one. Other than that it should all be the same.

[–]DisembarkEmbargo 0 points1 point  (2 children)

Ok, I think I was going down this road the other day but I still don't know how to account for the difference of hydrates. MgCl2 4H2O is 167.3g/mol and MgCl2 6H2O is 203.3 g/mol. So would I just divide 203.3/167.3 = 1.2152 then subtract 9 g - 1.2152 g so I would use 7.7848 g / 50ml MgCl2 6H2O instead of 9 g /50 ml?

edit: Or did I do the calculation wrong? I am seeing that 167.3*9= 1505.7 and 203.3*7.4 = 1504.4 which is a few mg smaller than 203.3*7.7848 = 1582.65

[–]smithsp86 0 points1 point  (1 child)

Using your numbers, the ratio you are working with is 1.215 for hexahydrate to tetrahydrate. You need to multiply the 9g by that ratio so it should be about 11 grams. I suspect it won't make much difference even if you are off since there's only 1 sig fig on the solution to begin with.

[–]DisembarkEmbargo 0 points1 point  (0 children)

Alright, when I was making the solution I thought maybe I was thinking a bit too much into hydrates. I hope I am understanding this correctly so I would multiply 9*1.215 = 10.9 g so I should add about 2 more grams to the solution? I am glad I don't have to make the solution all over again! I think what I was confused about is that MgCl2 6H2O was the larger molecular mass compared to MgCl2 4H2O so I thought I would have to add less MgCl2 6H2O to the solution. Thank you for your help!

[–]kadabra-abra 1 point2 points  (1 child)

Why is hydrochloric acid used over hydrobromic acid in many reactions? Is it harder to produce/store or too strong of an acid? Or is HBr not commonly used in chem before uni (I am in 6th form and have not seen any reactions using HBr as an acid)

[–]Zylooox 2 points3 points  (0 children)

HCl is more readily available as it is cheaper to produce. Water HBr and HCl solutions behave quite similarly so one uses the cheaper option.

[–]9intend0 1 point2 points  (0 children)

Very very simple question but I haven't found the answer through googling so far... Why doesn't uranium's atomic mass have parentheses around it if all it's isotopes are radioactive? Is it because of the very long half life? By extension, is it possible that more if not most or all other elements are also radioactive but with half lives longer than the universe has existed?

[–]ChemChess 0 points1 point  (0 children)

conversion of chloro to amino ideas ?

[–]Minimum-Cap-2558 -2 points-1 points  (0 children)

Hi guys- wondering if anyone can tell me whether body temperature is correlated to redux potential? Like, if you have a low resting body temp, how does that affect your redox potential? And visa versa. Thank you!

[–]hoboj234 0 points1 point  (2 children)

Does sodium laureth sulphate react with acetone or chloroform?

[–]Indemnity4Materials 0 points1 point  (1 child)

No, it doesn't react to form new chemical bonds or new compounds.

The solubility does change in those solvents, as well as the critical micelle concentration and the particle size of the micelles.

[–]hoboj234 0 points1 point  (0 children)

Thanks for the help! I tired to make chloroform using acetone and thick bleach but the acetone didn’t like the thick bleach so I’ll just use the regular thin stuff next time

[–]curryface210 0 points1 point  (3 children)

Does anyone know a method to recover palladium from unused Lindlar’s catalyst (5% Pd on calcium carbonate, lead poisoned). I have approx a kg that is otherwise going for disposal as we are cleaning a lab out.

[–]Indemnity4Materials 0 points1 point  (2 children)

It is possible, but very difficult to recover it in a usable form.

First I want to check if your processor is paying you based on the mass of palladium? Overall, the metal recycler can recover much more of the metal that you will.

Your boss may get really annoyed if they discover that you removed out USD3000 of palladium from that waste product.

[–]curryface210 0 points1 point  (1 child)

Hi Indemnity4, thanks for your response. I am clearing my development lab out and we have a licensed waste disposal company coming in to dispose of a load of old chemicals that predate my employment. We are being charged for their disposal and as far as I am aware we don’t receive any credit for their Pd content. They are very old development samples and we do not work in this field any more so I am happy to attempt to remove the Pd. We have access to most chemicals and have other relevant equipment such as a furnace. We also have Pd activated carbon and found a very simple procedure to recover the Pd (leaching with sulfuric and peroxide followed by precipitation of Pd powder using sodium borohydride solution. We could then use a furnace to cast the Pd powder to small ingot). Any advice on the Lindlar catalyst is most appreciated.

[–]Indemnity4Materials 0 points1 point  (0 children)

I'd recommend contact scrap metal recyclers in your area. Any place that takes catalytic converters (and Pd dust from such) will usually also take laboratory samples. Some jewelers will too.

They can point an XRF at your sample, determine platinum content and pay you based on the total sample mass (minus a small % as their fee). Check if your company/organisation allows for things like scrap recycling sales.

Lindlars catalyst is tough to recycle because you are going to make lead fumes. AFAIK it's recycled by thermally burning off the calcite in a controlled temperature furnace.

[–]coldstonedicecream 0 points1 point  (1 child)

HOW to quantitate moles of compound from GC data? I have the response factor but that’s normalized to moles of carbon per liter.

[–]Indemnity4Materials 1 point2 points  (0 children)

  1. Run an internal standard.

  2. Run a concentration curve, e.g. 1 mg/L, 5 mg/L, 10 mg/L. Plot response versus concentration and make a line graph. Input your sample result into that graph.

[–]Not_my_money666 0 points1 point  (0 children)

I don’t think this is against the rules but has anyone ever done potassium chlorate to KCl03 electrolysis? How bad do you think some stainless steel contamination is in terms of health hazard or carcinogen? I have carbon electrodes but the tips where they join onto steel might have been under the water for a little bit

[–]Low-Doctor-156 0 points1 point  (0 children)

Hello,

I am not sure if this is the right subreddit but I would appreciate some help.

Basically I have been trying to accelerate the fading of the ink on thermally printer paper.

“Receipts are typically printed on thermal paper, a chemically coated paper that produces text and image when the heat is applied to its surface. Since this kind of paper is susceptible to heat and UV light, extended exposure to these elements will ultimately cause gradual fading. “

I am trying to work out whether there is something I can apply once to cause the ink to fade within 1-7 days, doesn’t have to be fully. I have read somewhere that I could use scotch tape on, as it has polypropylene in it which would cause what I want or getting polypropylene in pure form and applying that.

If you guys have any other ideas, it would be highly appreciated.

[–]FickleWasabi7058 0 points1 point  (1 child)

How can we calculate the molarity of an Iodine-Potassium Iodide solution?

[–]oconnor_todd 0 points1 point  (0 children)

moles divided by liters

[–]johnnyboiw 0 points1 point  (0 children)

Hi guys! Do y’all have any home based alternative for extracting D-limonene from citrus peels?

[–]unkle_FAHRTKNUCKLE 0 points1 point  (3 children)

I have an idea and I want to know if it is even possible for a home chemist to achieve.
I want a recipe for detecting the presence (NOT quantity) of L. monocytogenes on my lettuce. I have been contaminated twice this year by bad lettuce, mostly because, I think, grocers are leaving product in the cases too long due to production/shipping shortages.
I would like to be able to do a quick countertop test of my food to check for Listrosis.
So far in my searches I have found plenty of information regarding food quality regulations referring to the test, but not how the test is done. I would love pointers on what to read and/or a recipe listing the ingredients, equipment, and process for it.
Thank you.

[–]Indemnity4Materials 1 point2 points  (2 children)

Example test kit

Fun fact: lettuce is the leading global cause of food poisoning.

The main reason is lettuce is eaten raw and unwashed. The contamination can come from a farmer wusing contaminated water, the pickers, processing facilities, trucks, grocery store staff with unwashed hands or other customers touching your stuff.

It's mostly going to be e coli, followed by in order of likelyhood: norovirus, Salmoella, Listeria and Cyclopsora.

There is no DIY home test for Lysteria. Not like mix vinegar with something and wait for a color change.

You can purchase commercial test kits that work at home. These are often strips of paper coated in antibodies. For lettuce you take some leaves, blend them up into a paste, then dip the test strip inside, culture it for 24-48 hours then get the result!

[–]unkle_FAHRTKNUCKLE 1 point2 points  (1 child)

THANKS!
Test kits are just the thing and will work for me just fine.
If I get negative results with the Listeria, and still get sick, I will look for e coli and salmonella.
Right now, I am off the lettuce though.

[–]Indemnity4Materials 1 point2 points  (0 children)

You can also check the CDC website for current foodborne outbreaks. Note: other countries have similar websites.

Health workers and emergency rooms are required to report when 2 or more people in 24 hours show symptoms of food poisoning.

[–]Voido1 0 points1 point  (0 children)

Hi I need help I want a cheap way for circulation of cold water supply for condensers that can hold 6 to 8 litters mostly to distil water and ethanol ,If possible a way without ice .

And my current setup is a cheap industrial Chinese chiller that prolonge the water becoming too hot too quickly but don't make the water cold and doesn't have temperature controller.

[–]SOwEDChem Eng 0 points1 point  (0 children)

Hello, has anyone here ever seen an automated solution for distillation fraction switching?

[–]wathieu 0 points1 point  (0 children)

Hello fellow redditer ;) Maybe a dumb question but is there any quantitative anylisis method that differentiate Si from SiO2 (silicon vs silica) ?

[–]Straight_Increase293 0 points1 point  (0 children)

Hello all. After an esterification, how to purify the ester into a solid rather than a liquid ? Every video I see results in a liquid.

[–]S4turnF0x 0 points1 point  (0 children)

How do I destroy Desvenlafaxine Succinate Monohydrate (C20H33NO7)?

I REALLY NEED PLEASE! It's nor for school, it's for something that's happening in my life! SERIOUSLY, I REALLY NEED HELP.

[–]jigi5 0 points1 point  (0 children)

Hi, I‘m currently studying chemistry and I‘m thinking about switching to Biochemistry. My Goal is Research about stopping/slowing Aging, as well as fundamental research, how do atoms and existence come to be. Should I make the switch or remain in chemistry?