Sciencemadness Discussion Board - The Short Questions Thread (4)

The Short Questions Thread (4)

Pages: 1 .. 11 12 13 14 15 .. 26

j_sum1 - 6-1-2016 at 16:46

Quote: Originally posted by The Chemistry Kingdom

Is it possible to obtain hydrogen peroxide from sodium persulfate

If you know the answer please reply I am cuurently looking at alternative methods for obtaining hydrogen peroxide because it is a bit costly

I was wondering about this a couple of days ago. I hadn't gotten to looking it up though.
If there is an answer, I would love to know it.

In answer to my own question. Arrowroot is a good soluble starch.
Ingredients: Tapioca Flour
Contains sulfites

I managed to get half a teaspoon to dissolve in less than 100mL of water. It is slightly cloudy but no sediment has formed overnight.

The Volatile Chemist - 6-1-2016 at 17:49

In regards to the persulfate, I know it works because it came up in an electrolysis book in the SM library. Sorry, I can't provide a reference as it is late.

Sulaiman - 7-1-2016 at 01:19

for H2O2 maybe use sodium percarbonate ?
OTC OxiClean, Oxy Clean etc. non-bio whitener
(bleach, e.g. 2Na2CO3.3H2O2 → 2Na2CO3 + 3H2O2 ,when added to water)
better to buy 'pure' sodium percarbonate as the OTC is 15% to 30%

EDIT e.g. http://www.ebay.co.uk/itm/172032224041?_trksid=p2060353.m143...

[Edited on 7-1-2016 by Sulaiman]

crystal grower - 7-1-2016 at 02:18

I want to grow sulfur crystals from toluene solution
What do you think is the best technique?
Cooling heated solution or slow vaporisation of toluene ??

j_sum1 - 7-1-2016 at 02:33

Quote: Originally posted by crystal grower

I want to grow sulfur crystals from toluene solution
What do you think is the best technique?
Cooling heated solution or slow vaporisation of toluene ??

I did it with xylene a couple of months ago. Pix are in the pretty pictures thread.

Procedure was simple. I heated the xylene in a beaker and stirred in sulfur as it heated. At about 110C I had a nice yellow solution with a lot of S in it. Maybe 40% by mass. Crystals grew as it cooled.

Interested in your results. Mine were long needles. I think toluene gives a more regular shape.

crystal grower - 7-1-2016 at 06:48

Quote: Originally posted by j_sum1

Quote: Originally posted by crystal grower

I want to grow sulfur crystals from toluene solution
What do you think is the best technique?
Cooling heated solution or slow vaporisation of toluene ??

Thanks for answer .
Aren't long needles more likely caused by high temperature than by type of dissolvent ??

[Edited on 7-1-2016 by crystal grower]

arkoma - 8-1-2016 at 17:27

have crude, dark KOH from oak ashes--decolorizing advice?

blogfast25 - 8-1-2016 at 19:14

Quote: Originally posted by arkoma

have crude, dark KOH from oak ashes--decolorizing advice?

What you have is crude, dark K₂CO₃ from oak ashes.

Oak ashes don't contain any KOH, mainly K₂CO₃.

Try active charcoal or a bit of hydrogen peroxide to get rid of the brown stuff.

[Edited on 9-1-2016 by blogfast25]

arkoma - 9-1-2016 at 12:11

Thanx Blog. So to get KOH:

K₂CO₃ + HCl then electrolyze the resultant salt?

It was throwing me because of the high pH and the fact the leachate is referred to as "lye".

blogfast25 - 9-1-2016 at 12:36

Quote: Originally posted by arkoma

Thanx Blog. So to get KOH:

K₂CO₃ + HCl then electrolyze the resultant salt?

Easier: react it with slaked lime:

Ca(OH)₂(s,aq) + K₂CO₃(aq) === > CaCO₃(s) + 2 KOH(aq)

Filter off CaCO₃.

Ordering 1st ground glass joint glassware

highpower48 - 9-1-2016 at 15:57

I'm ordering my 1st ground glass joint glassware. It will be Chinese made( all I can afford right now) I know it's not the best, but I have a question. Should I go with 24/29 or 24/40 joint sizes both seem to be about the same in pricing? I know that 24/40 is suppost to be the best, But there does seem to be more variety in the 24/29 joint sizes. Just ordering a distillation kit and a vacuum filtering kit.

Pyro - 9-1-2016 at 15:59

It doesn't really matter, both are pretty much interchangeable.
If you really want to pick one, pick the one most used in your region. (US or Europe?)

j_sum1 - 9-1-2016 at 16:45

I like 24/40. I think it gives a more robust joint. I have a little 24/29 and have not had any compatibility issues.

One advantage of the larger size: I chipped the edge of a flask. It is still usable. With a smaller joint there would have been insufficient surface left to make a join.

j_sum1 - 11-1-2016 at 20:26

I recently obtained some pool sanitiser -- active ingredient lithium hypochlorite.
On reading the MSDS I have found that it is only 30% LiOCl with the remainder, "alkaline components". A flame test gives the characteristic colour of sodium -- sufficient to mask any Li to the naked eye. I am going to guess in the absence of better information that the additional compound is either sodium hydroxide or sodium carbonate. I intend some stage soon to do a titration to determine how much hypochlorite is there.

Any suggestions on how I might best determine the composition of what I have and also how to obtain a relatively pure lithium compound from this mix?

Tabun - 12-1-2016 at 11:00

Is there any book or something where I can check a substance's important proprierties like...toxicity?Especially related to nitro groups and single/triple bonds.

[Edited on 12-1-2016 by Tabun]

Sources of Phosphorus?

CitricAcid - 12-1-2016 at 22:12

I would like to know about any other sources of phosphorus besides matchboxes. There is a website called onyxmet.com. I ordered a few grams of red P to make phosphorus tribromide,which I ultimately used for methyl bromide. Since I will likely be visited by police if I try to order any more phosphorus,I would like to know about any possible sources of P besides scraping matchboxes.

[Edited on 13-1-2016 by CitricAcid]

macckone - 12-1-2016 at 22:16

See the thread on making phosphorus using an aluminothermic reaction.

UC235 - 13-1-2016 at 10:51

Why on earth would you use PBr3 for methyl bromide. A mixture of methanol, sulfuric acid, and NaBr is quite sufficient.

j_sum1 - 14-1-2016 at 03:15

An answer

Quote: Originally posted by The Chemistry Kingdom

Quote: Originally posted by The Volatile Chemist

In regards to the persulfate, I know it works because it came up in an electrolysis book in the SM library. Sorry, I can't provide a reference as it is late.

I have done a bit of research on this. See this thread and the resource I added.
http://www.sciencemadness.org/talk/viewthread.php?tid=16151&...

Another answer

Quote: Originally posted by kemster90

Is there a chemical which can decompose bleach into oxygen without being consumed like maganese dioxide for sodium chlorate

You can use CoCl2 as a catalyst. The hypochlorite will decompose quite readily liberating wet O2 gas. I don't think much Cl2 is liberated in the process -- certainly not enough to smell.
If you are careful to not let the container overflow, then you can attempt to recover the CoCl2.

HeYBrO - 14-1-2016 at 16:30

Quote: Originally posted by j_sum1

Soluble starch

I have searched the forum and a few other places but have not found good answers to this question.
I am after some soluble starch for use in redox titrations. I know I can buy some from a chemical supplier but I was wondering about otc sources and preparations. I didn't think it would be too hard -- in fact, it is probably so basic that no one writes much on it. Here is what I have tried and my thoughts so far.

1. I have thus far used white rice and washed it with cold water and collected the water from it. This has been somewhat successful in the past but my last attempt produced something that was not sensitive enough. I have also used hot water but always gotten a cloudy mixture that was not really any better for the task.

2. I have read a few very simple procedures for obtaining potato starch. Basically juice a potato and dry it. I am not sure how good this would be for iodometry. It is usually presented as a the first step in making a simple plastic product. I think that the starch obtained is quite soluble though.

3. There are quite a number of starchy products available at the supermarket. What the Americans call cornstarch is called cornflour here and I am not sure how it is processed or how it will act. Again, it is not that soluble. Arrowroot seems like it would be a better option. Alas, old-fashioned laundry starch has been replaced by ezi-iron.

4. There are numerous papers available that describe ways of making starch more soluble. There are modified starches. There are procedures for separating it from gluten and other proteins. It can be made into pre-gelatinised starch through a laborious process of soaking in DMSO and then baking for a long period. There is also the possibility of treating it with alkali or "a salt" to make it more soluble. I am not sure how one then effectively gets rid of the alkali or salt or even if it matters too much. I guess if I used ammonia then any excess would evaporate away.

So, (and I know I am probably overthinking this) what is the best course of action? Is juicing a potato ok? Or should I buy some tapioca flour? Is it worth treating it in any way? Or is best to spend a couple of bucks at a chem supplier?

did you see this: https://www.youtube.com/watch?v=rypuMg-r3zM?

j_sum1 - 14-1-2016 at 16:59

Thanks HeYBrO.
That is a cool procedure with the glycerine. I have found that arrowroot is pretty soluble and seems to work quite well. I wonder if I could get an even better product by combining the two approaches.

I also bookmarked that channel. It seems that there is quite a bit of good stuff there. Might be a language barrier in places however.

How do I identify ammonium bisulfate vs ammonium sulfate (has it converted to bisulfate)

RogueRose - 14-1-2016 at 20:06

When I was working on purification of Amm Sulfate, I wasn't aware that it would decompose to bisulfate at 212F. I allowed a pot of water/amm sulfate solution to reach boiling and then evap'd some in an open glass dish at a temp above 212 (about 350 in oven actually). I had misread the properties of sulfate and didn't know about this on my first run and in the middle of second.

I'm curious if everything in the pot that was in solution would have decomposed into the bisulfate or if it should be alright. Also what about the part that was evap'd at 350.

I've tried finding info about the bisulfate and there is very little info about it and it's uses.

I can say that I noticed VERY little ammonia smell at any time during this process. I would say that the scent from a single spray of Windex would have smelled stronger and lasted longer than the boiling and I noticed no smell during evap.

I would think that since the bisulfate looses 1/2 the ammonia per weight then I would have had a pretty strong smell of ammonia when doing this.

What do you guys think? Is there a way to test this?

DraconicAcid - 14-1-2016 at 20:11

If you dissolve some in water, ammonium bisulphate will be much more acidic than ammonium sulphate.

annaandherdad - 14-1-2016 at 20:54

Quote: Originally posted by DraconicAcid

If you dissolve some in water, ammonium bisulphate will be much more acidic than ammonium sulphate.

Yes, and then you could neutralize it with ammonia and be back to ammonium sulfate.

Removing water from Ammonia Cleaner

RogueRose - 16-1-2016 at 07:57

I was thinking about how corn meal is used in removing the last bit of water from alcohol, I think I have read that things like anhydrous MgSO4 can be used as well.

Could either of these be used to absorb water from a standard ammonia cleaning solution?

Detonationology - 16-1-2016 at 08:42

Standard household ammonia is 3-7% NH4OH (NH3 in water). If one wished to increase the concentration of NH4OH in solution, I think the only way to do that would be to bubble more NH3 through the solution, which would react with the water. I have never heard of an NH4OH solution exceeding 27-30% (just under 1 mol per 100g H2O), probably because at such high concentrations, the ammonia gas and water are more favorable.

BTW, household ammonia contains surfactants. A 10% solution of surfactant-free janitorial ammonia can be found at ACE Hardware.

hissingnoise - 16-1-2016 at 09:20

Ammonium hydroxide is essentially an ammonia/water solution!

NH₃ + H2O <─> NH₄<sup>+</sup> OH<sup>−</sup>

The equilibrium is well to the right and NH₃ escapes with evaporation and increase in temp. so that it cannot be dehydrated . . .

Gaseous ammonia may be added using an inverted funnel, with stirring, to increase concentration!

DraconicAcid - 16-1-2016 at 10:55

I've long insisted that "ammonium hydroxide" is a misnomer for aqueous ammonia, used only because of Arrhenius' insistence that hydroxide was the only base in existence.

The Volatile Chemist - 20-1-2016 at 17:40

Quote: Originally posted by hissingnoise

Gaseous ammonia may be added using an inverted funnel, with stirring, to increase concentration!

...But heating the solution allows one to bubble ammonia gas into a vessel, so it at the very least a useful method to isolate ammonia.

What kind of cotton comes in the top of medicine/pill bottles?

RogueRose - 21-1-2016 at 14:10

It has been some time since I've opened medicine bottles that had a large wad of cotton at the top of the container but I'm wondering if that kind of cotton has a name. It isn't cotton balls, swabs, pads or gauze (well I guess it could possibly be considered a type of gauze??). I'm guessing that it may be similar to what may be inside a tampon??

Anyway, I'm trying to find it in bags, rolls or whatever it may come in. I've tried the other types of cotton products and it doesn't work nearly as well as this for various uses. I've tried polyester fillling/stuffing but it doesn't work for what I need as the fibers aren't really absorbent in the same way and they don't retain "dirts" as well either.

Does anyone know what this stuff might be called or even where it may be gotten?

chemrox - 21-1-2016 at 16:44

usually cellulose i.e. cotton from agricultural sources.

DubaiAmateurRocketry - 23-1-2016 at 13:55

Does anyone know if this is true ?

So I was thinking about falling into a black hole few days ago. I summarized my thoughts that you should be able to see everything that will able to happen to the universe since when you're very close to black hole, time dialation start to significantly slow down, that you would never technically physically enter it since that also means the black hole will be evaporated from hawking radiation relative to the outside world ? Because as you close in onto a black hole, time relative to outside passes so slow, hawking radiation significantly happens faster, almost instantaneous.

Morgan - 23-1-2016 at 14:41

Quote: Originally posted by RogueRose

It has been some time since I've opened medicine bottles that had a large wad of cotton at the top of the container but I'm wondering if that kind of cotton has a name. It isn't cotton balls, swabs, pads or gauze (well I guess it could possibly be considered a type of gauze??). I'm guessing that it may be similar to what may be inside a tampon??

"First, your downy plug might be cotton, but, equally likely it's rayon or polyester. Second, an organization called the United States Pharmacopoeia (USP), which has set quality standards for U.S. medicines for nearly 200 years, establishes criteria for that cotton. Not just anything goes."

Source: Why Is There Cotton In My Medicine Bottle? - Drugsdb.com http://www.drugsdb.com/blog/why-is-there-cotton-in-my-medici...

j_sum1 - 24-1-2016 at 18:50

Am I correct in thinking that this compound shows Cr in a +7 state?
http://cen.acs.org/articles/94/i4/Chromium-Nitrogen-Complex-...

The article shows a newly synthesised complex with single, double and triple bonds between Nitrogen and the same Chromium atom. But I am not really understanding how the molecule works. There appears to be an additional ligand that I was not expecting.

(Also in the news -- 1,1,2,2,tetranitroethane. Developed to possibly replace ammonium perchlorate but tends to go off with a bit of a bang.)

Lithium - 24-1-2016 at 19:31

@j_sum1 if you are still trying to separate the lithium from unknown sodium salts, a possibility is taking advantage of lithium carbonate's decreased solubility at higher temperatures in water [the industrial exploitation of this property is mentioned in passing here:https://en.m.wikipedia.org/wiki/Lithium_carbonate under properties and reactions, while specific numbers are given under properties] sorry I can't give any good references here I'm on my phone.

I would either add an excess of HCl to convert all salts to chloride, and then apply sodium carbonate and precipitate the lithium carbonate while hot, or boil a solution of the material to convert the hypochlorite to chlorate, precipitate the lithium carbonate with sodium carbonate and filter while hot, and add potassium chloride to obtain potassium chlorate aswell.

Depends what you have already (i.e. HCl or KCl) and if you could do with some KClO3 or Cl2.

Haven't performed anything like this myself.

j_sum1 - 24-1-2016 at 21:23

Thanks so much for that Li. (Appropriate post/username combo. Also, nice to spot another fellow countryman.)

It sounds like an exacting sort of a process, but a worthwhile sort of project for building up some skills. I might have to do it on a small scale. I lack the KCl to convert the whole bucket.

Incidentally, I attempted some iodometry with it the other day. (Or was it iodimetry -- I always conflate the two) It misbehaved and I did not get a result. So I am not sure what the "alkaline components" mentioned in the MSDS are. I had assumed NaOH as the most likely possibility. Whatever it was, it affected the formation of iodine-starch complex. I haven't figured out what was going on. I will have to study it a bit more closely before I have another attempt.

Velzee - 26-1-2016 at 16:26

Alright, how can I compress powdered charcoal into rods?

MgOH from MgSO4 + Ammonia - different results than expected

RogueRose - 27-1-2016 at 12:38

I thought I would see how Mag Hydroxide would form from two different methods of preparation. In one beaker I mixed 100ml dH2O and 100ml ammonia solution then added about 60g of MgSO4 and stirred until dissolved. In another beaker I dissolved 60g of MgSO4 into 100ml dH2O and then added the 100ml ammonia.

The first beaker resulted in what seemed like crystals growing in solution, although not crystals - it was patchy formation of precipitate. The second beaker slowly turned from totally clear to opaque over about 20-30 mins.

After a few days of settling the second beaker had about 10x the amount of MgSo4 on the bottom of the beaker and it seemed much smoother (like how it is in milk of mag) the first beaker had what looked like sludge snotty white precipitate.

I looked at some videos about making MgOH this way and some say that 99% Isopropanol is needed to make the MgOH precipitate, while other pages say nothing about it.

Can anyone clear up why I might have gotten such different results from this and if the rubbing alcohol is actually needed?

The Volatile Chemist - 28-1-2016 at 08:50

Quote: Originally posted by Velzee

Alright, how can I compress powdered charcoal into rods?

You could always dissect a 6v battery to get four carbon rods. I don't think making them is very feasible, though.

Velzee - 28-1-2016 at 16:28

Okay, I went out searching for any radioactive rock specimens near my home( I found one), and I found this other guy here(who seems not to be radioactive):

So I want to know if this is coal(specifically anthracite coal), any guesses?
It's light, has a metallic luster with a few brownish spots here and there. I actually find quite a bit of this stuff scattered around my neighborhood. All on the surface/stick out to the surface.

EDIT: With some effort, it even writes like a very fine, very light pencil.

[Edited on 1/29/2016 by Velzee]

[Edited on 1/29/2016 by Velzee]

elementcollector1 - 28-1-2016 at 18:39

Weight/density, if you can? That'd be a pretty good indicator. Is the streak light gray or dark gray?

In my experience, anthracite is a pretty brittle material, and powders all too easily.

If not, could it be graphite?

ganger631 - 29-1-2016 at 00:01

Hi all, i have a patch of carbon stuck around the frosted joint. Is there anyway of removing it without using strong oxidant chemical? i tried scrubbing it, washing it with base, however it hasn't been very effective. I do not have the material to make chromic acid and do not want use a solution of sulfuric acid and h2o2. Thanks

Velzee - 29-1-2016 at 05:27

Quote: Originally posted by elementcollector1

Weight/density, if you can? That'd be a pretty good indicator. Is the streak light gray or dark gray?

In my experience, anthracite is a pretty brittle material, and powders all too easily.

If not, could it be graphite?

I found the density to be around 1.24g/cc. I don't have anything suitable as a streak plate, so I can't tell you that.

[Edited on 1/29/2016 by Velzee]

blogfast25 - 29-1-2016 at 06:00

Quote: Originally posted by Velzee

Quote: Originally posted by elementcollector1

I found the density to be around 1.24g/cc. I don't have anything suitable as a streak plate, so I can't tell you that.

Chip off a small chunk and see if you can get it to burn? Use a Bunsen or alcohol burner to heat it up sufficiently.

Carbon also reacts with concentrated nitric acid and concentrated NaOH.

[Edited on 29-1-2016 by blogfast25]

Velzee - 29-1-2016 at 10:33

Quote: Originally posted by blogfast25

Quote: Originally posted by Velzee

Quote: Originally posted by elementcollector1

I found the density to be around 1.24g/cc. I don't have anything suitable as a streak plate, so I can't tell you that.

Chipping off a piece was really easy. Placing the piece in the flame of a stove top burner caused the edges to glow orange, and after a minute of heating, the glowing edge turned a white ashy color. The piece fell into stove top, but it never took a flame.

Sodium ferrocyanide (yellow prussiate of soda)

lysander - 31-1-2016 at 08:44

Yellow prussiate of soda is a common anti-caking agent, but I can't find it for sale as a reagent anywhere. Am I missing something?

Texium - 31-1-2016 at 08:50

Not a very good deal, but this is the first thing that came up on Google shopping: http://www.rakuten.com/prod/sodium-ferrocyanide-laboratory-c...

(Searching for things by their real names rather than using weird archaic ones sometimes leads to better results)

UC235 - 31-1-2016 at 09:18

http://www.elementalscientific.net/store/scripts/prodView.as...

Sodium ferrocyanide

lysander - 31-1-2016 at 09:37

Quote: Originally posted by zts16

Not a very good deal, but this is the first thing that came up on Google shopping: http://www.rakuten.com/prod/sodium-ferrocyanide-laboratory-c...

Oh wait, is this a regulated chemical in the U.S.? I've gotten so used to easy access to K-ferrocyanide I didn't consider there might be a difference with the Na salt.

elementcollector1 - 31-1-2016 at 09:45

Quote: Originally posted by Velzee

Sounds exactly like the anthracite I worked with - that stuff needs air influx and strong ignition (kerosene, etc.) to even light.

Texium - 31-1-2016 at 11:02

Quote: Originally posted by lysander

Quote: Originally posted by zts16

Not a very good deal, but this is the first thing that came up on Google shopping: http://www.rakuten.com/prod/sodium-ferrocyanide-laboratory-c...

Oh wait, is this a regulated chemical in the U.S.? I've gotten so used to easy access to K-ferrocyanide I didn't consider there might be a difference with the Na salt.

Nope, not regulated at all. It's just that the potassium salt is used more often for some reason. I'm not sure why, being as usually sodium salts are less expensive, the two are made by the same process, and can be used interchangeably most of the time. It's also not one of those situations where the sodium salt is hygroscopic, which seems to be one of the main reasons why potassium salts are preferred in some cases, such as with bisulfate.

Sodium ferrocyanide

lysander - 31-1-2016 at 12:52

Quote: Originally posted by zts16

Well both ferrocyanides are hygroscopic -- the K-salt forms a trihydrate and the Na-salt forms a decahydrate. But while I can find plenty of suppliers of bulk K-ferrocyanide the only bulk Na-ferrocyanide I have found so far is from a U.S. supplier in OK on ebay claiming a bizarre set of "hazardous chemical" regulations apply to this common anti-caking agent!

Texium - 31-1-2016 at 12:53

Sorry, I meant to say deliquescent.

JJay - 31-1-2016 at 13:01

Quote: Originally posted by Velzee

Okay, I went out searching for any radioactive rock specimens near my home( I found one), and I found this other guy here(who seems not to be radioactive):

So I want to know if this is coal(specifically anthracite coal), any guesses?
It's light, has a metallic luster with a few brownish spots here and there. I actually find quite a bit of this stuff scattered around my neighborhood. All on the surface/stick out to the surface.

EDIT: With some effort, it even writes like a very fine, very light pencil.

[Edited on 1/29/2016 by Velzee]

[Edited on 1/29/2016 by Velzee]

That looks like shale, but it's hard to be really sure from the image.

Solvent substitution

Deathunter88 - 2-2-2016 at 23:23

Are there any good alternative solvents for acetone (regulated drug precursor)? I want something similar to acetone that I can use to rinse glassware after washing and something that is good at removing glue. The usual substitutes such as MEK, ether, and chloroform are out since they are drug precursors too. I'm thinking ethanol for rinsing glassware but I am not sure. While on this topic, is xylene a good substitute for toluene(also drug precursor) in regards to it's solvent properties, such as for recrystallizing things? If not are there good substitutes for toluene?

greenlight - 3-2-2016 at 01:57

I have used 99% Ethanol for washing glassware before and it does a good job, I usually use acetone though and find it the best for regular cleaning. Sucks you can't purchase it in your country. I don't really see how it is an actual precursor for illicit drugs, maybe to clean and crystallize the final product but not for the actual synthesis.

I am sure that you can use xylene as a substitute for toluene for general solvent properties like you state.

Question about ball mill

confused - 3-2-2016 at 03:45

I'm trying to make a ball mill to increase the surface area of various metals and chemicals (stuff always clumps

)
I'm trying to use glass marbles as grinding media, is there anything i should take note of, If i'm not grinding any energetic materials

Deathunter88 - 3-2-2016 at 04:46

Quote: Originally posted by greenlight

I have used 99% Ethanol for washing glassware before and it does a good job, I usually use acetone though and find it the best for regular cleaning. Sucks you can't purchase it in your country. I don't really see how it is an actual precursor for illicit drugs, maybe to clean and crystallize the final product but not for the actual synthesis.

I am sure that you can use xylene as a substitute for toluene for general solvent properties like you state.

Thanks for your answer. I'll use ethanol from now on to wash glassware.

Deathunter88 - 3-2-2016 at 04:48

Quote: Originally posted by confused

I'm trying to make a ball mill to increase the surface area of various metals and chemicals (stuff always clumps

)
I'm trying to use glass marbles as grinding media, is there anything i should take note of, If i'm not grinding any energetic materials

Using glass as grinding media can have the issue of getting glass chips mixed with your chemicals. I wouldn't grind the chemicals as I think it will only make the clumping worse. Also, finer chemicals also means more dust which can be annoying.

The Volatile Chemist - 3-2-2016 at 16:02

Indeed, dust is annoying. In regards to finding Potassium Ferrocyanide, you'd be best buying it. Since the sodium salt is about 1/3 as soluble as the potassium one, I'd try crystallizing the sodium salt from the potassium one and sufficient table salt.

[Edited on 2-4-2016 by The Volatile Chemist]

what are the most easily available nickel compounds & their uses

bluamine - 4-2-2016 at 09:05

Hi everyone!!!
I want to use nickel as a catalyst for several reactions, & I hope I will find someone who can help me. I would like to know easily home-available chemicals containing it.

UC235 - 4-2-2016 at 09:18

Nickel salts are carcinogenic and allergenic in a large portion of the population, so they are found in no consumer products. You might be able to buy oxide or carbonate as an additive for pottery glazes, but that's all. Buy nickel metal and make your own starting from nickel nitrate.

[Edited on 4-2-2016 by UC235]

PHILOU Zrealone - 4-2-2016 at 15:26

Quote: Originally posted by bluamine

Hi everyone!!!
I want to use nickel as a catalyst for several reactions, & I hope I will find someone who can help me. I would like to know easily home-available chemicals containing it.

Hint coins and metalic money often contain such an element.
Even if its use is reduced you may stil find nickel to some extend into 1€ and 2€ coins...aside with copper and other metals.

1 Euro coins: 7,50g
-Bronze External ring contains nickel brass (maillechort)
75% Cu, 20% Zn and 5% Ni (75 Cu/20 Zn/5 Ni)
-Silver Internal ring contains layers of copper-nickel alloy (75% Cu and 25% Ni - 75 Cu/25 Ni + traces of Mn) and nickel

2 Euro coins: 8,50g
-Silver External ring contains copper-nickel alloy (75% Cu and 25% Ni - 75 Cu/25 Ni + traces of Mn).
-Bronze Internal ring contains layers of nickel brass (maillechort)
75% Cu, 20% Zn and 5% Ni (75 Cu/20 Zn/5 Ni) and nickel

Of course dissolving 1€ and 2€ coins in sulfuric or nitric acid is against the laws because you destroy money.

So don't tell anyone where your Ni comes from

[Edited on 5-2-2016 by PHILOU Zrealone]

DraconicAcid - 5-2-2016 at 20:47

Quote: Originally posted by UC235

Quote: Originally posted by learningChem

Is it possible to reduce 3 nitrobenzoic acid to 3 aminobenzoic acid using the Fe/HCl method?

Yes. Tin and HCl would also work. However, I would recommend using a reducing agent in basic media instead. Having soluble 3-nitrobenzoate will improve reaction speed.

Options are sodium dithionite/hydrosulfite, thiourea dioxide in NaOH or NH3 solution or Na2S (which reeks and poses a hazard on neutralization).

Would aluminum in sodium hydroxide work?

UC235 - 5-2-2016 at 20:52

Quote: Originally posted by DraconicAcid

Quote: Originally posted by UC235

Quote: Originally posted by learningChem

Is it possible to reduce 3 nitrobenzoic acid to 3 aminobenzoic acid using the Fe/HCl method?

Would aluminum in sodium hydroxide work?

I would guess rather poorly, but maybe. Workup would probably be terrible from gelatinous aluminum hydroxide. Avoiding reduction to nitrosobenzene, azobenzene, phenylhydroxylamine and hydrazobenzenes is important. As far as I know, zinc in NaOH typically produces hydrazobenzene which is then acidified for the benzidine rearrangement. Aluminum may be similar.

Hydrosulfite is the classical last step for luminol production to reduce an aromatic nitro group in basic conditions. I have successfully used thiourea dioxide in its place based on a paper that reduces a wide range of aromatic nitro compounds to anilines using it.

Na2S is a classic, albeit smelly approach to anilines.

You caught me before I deleted the comment. I accidentally replied to something from page 26.

[Edited on 6-2-2016 by UC235]

Boiling point.

Romix - 8-2-2016 at 02:40

Why alcohols have lower boiling point then water.

They all have heavier molecular mass then H2O, but boils at lower temp.
Maybe because of attractions between molecules, and water needs more energy to brake these? Or no?

[Edited on 8-2-2016 by Romix]

hissingnoise - 8-2-2016 at 03:18

Quote:

Maybe because of attractions between molecules, and water needs more energy to brake these?

Essentially yes! Ethanol is less polar than water . . .

Solvent relative polarities.

Fulmen - 8-2-2016 at 03:51

Good question and you're absolutely right about the cause:
http://chemistry.elmhurst.edu/vchembook/163boilingpt.html

Magpie - 8-2-2016 at 09:04

"hydrogen bonding" for the water.

reaction of red phosphorus and ammonium hydroxide

symboom - 13-2-2016 at 01:26

ive mixed the two in a process to extract potassium chlorate from matches and part of it is to add ammonium hydroxide to the mix. Not sure if it is a reaction or so it seems is it reacting if so what is formed or

[Edited on 13-2-2016 by symboom]

j_sum1 - 14-2-2016 at 02:19

I have decided that I will prepare a silver mirror and a copper mirror (using hydrazine) on the inside of some ampoules for my element collection.
Is a gold mirror also possible? I have tried searching for "gold mirror" but can't get past all the junk. (Need to improve my googe-fu.) I assume that it is possible but have not found a procedure.

Faulty pH meter

j_sum1 - 14-2-2016 at 03:00

I have a pH meter similar to the one shown.
meStez9KXzwEPE4kUEZIVjg.jpg - 14kB

I went to use it today and found it reading abnormally high -- 9.5 for something that should be neutral or close to it. (Swimming pool.)
I keep it in a screw-top jar in a buffer solution at 6.86.

What may have happened to it? Is there anything that can be done to restore it? Or do i just need to replace it?

What can I do with tin?

Kagutsuchi - 19-2-2016 at 13:33

I recently found out that I have about 10 kg of very fine tin powder. Any ideas what could I do with it?

Metacelsus - 19-2-2016 at 15:22

You could use it with HCl for reductions (for example, nitrotoluene to toluidine).

CharlieA - 19-2-2016 at 19:03

Quote: Originally posted by j_sum1

I have a pH meter similar to the one shown.

I went to use it today and found it reading abnormally high -- 9.5 for something that should be neutral or close to it. (Swimming pool.)
I keep it in a screw-top jar in a buffer solution at 6.86.

What may have happened to it? Is there anything that can be done to restore it? Or do i just need to replace it?

I have a similar meter and just rechecked the calibration after the probe had been dry for a couple of months. After hydrating in D. H2O for 15', I than checked two buffers and both were right on...but forget the hundredths reading. Certainly the accuracy to 0.1 pH unit is satisfactory.

Do you have an independent measurement of the pH of your pool water? Even test papers like pHydrion paper or litmus paper (you need to check with both red and blue papers) could give you some idea. Is the pool chlorinated now?

Solvent for glue

Romix - 19-2-2016 at 19:08

Please recomend solvent, that will easily dissolve glue.

I tried 2-propanol, cold and boiling hot. Not dissolving it.
Glue that hold rubber to pcb.

j_sum1 - 19-2-2016 at 19:52

The pool is an inflatable with no pump or filter. I give it a few pool chemicals to make the water last a bit longer for the kids.

Yes I checked it with both pH paper and phenol red. The meter is reading high.

The meter has never gotten dry. It is kept in a buffered solution which, as far as I can tell is unchanged - close to neutral.

Detonationology - 19-2-2016 at 20:20

What kind of glue? Maybe try acetone.

NedsHead - 19-2-2016 at 20:39

My PH meter recommends using only a storage solution and it came with a small bottle, after the small bottle of solution ran out I have been storing it in tap water without any issues, storing them in distilled water will ruin them, I'm not sure about 6.86 buffer though

[Edited on 20-2-2016 by NedsHead]

Great - 19-2-2016 at 20:56

Quote: Originally posted by symboom

ive mixed the two in a process to extract potassium chlorate from matches and part of it is to add ammonium hydroxide to the mix. Not sure if it is a reaction or so it seems is it reacting if so what is formed or

[Edited on 13-2-2016 by symboom]

I think a soluble hypophosphite is formed

Kagutsuchi - 20-2-2016 at 10:30

Quote: Originally posted by Cheddite Cheese

You could use it with HCl for reductions (for example, nitrotoluene to toluidine).

Can I do that with gray tin, too? So the covalent allotrope. Because that is what I have.

DraconicAcid - 20-2-2016 at 10:34

Quote: Originally posted by Kagutsuchi

Quote: Originally posted by Cheddite Cheese

You could use it with HCl for reductions (for example, nitrotoluene to toluidine).

Can I do that with gray tin, too? So the covalent allotrope. Because that is what I have.

Should work with either.

That reminds me- I was going to put a bit of tin in the freezer, to see if it changed.

arkoma - 21-2-2016 at 17:33

WTF is a zeotrope?

j_sum1 - 21-2-2016 at 17:35

Quote: Originally posted by arkoma

WTF is a zeotrope?

azeotrope?
https://en.wikipedia.org/wiki/Azeotrope

arkoma - 21-2-2016 at 17:42

nope ZEOTROPE. I'm wondering if I can fract distill the water off of 5% AcOH. I've read the wiki on zeotropes but it is ambiguous to my somewhat fractured brain.

NedsHead - 21-2-2016 at 17:59

closest thing I could find was Zeotropic Mixture? https://en.wikipedia.org/wiki/Zeotropic_mixture

UC235 - 21-2-2016 at 21:45

Yes, acetic acid and water are a zeotropic mixture. That is, they do not form an azeotrope and can be separated by distillation. Note that this fractionation is considered exceptionally difficult due to the close boiling points. A packed column with a significant number of theoretical plates and a high reflux ratio will be needed.

Using a smaller column like a vigreux or even a slow simple distillation, you will be able to concentrate the acetic acid but it will not be anhydrous or near it, especially for the latter option.

DraconicAcid - 22-2-2016 at 11:44

In words derived from Greek, a- or an- means "not" or "without". So atheist is the opposite of theist, anisotropic is the opposite of isotropic, agnostic is the opposite of gnostic, and an anaphrodisiac is the opposite of an aphrodisiac.

arkoma - 23-2-2016 at 06:59

Thanx UC. Have a vigreux and since I need to keep my mind off the possible tornadoes later today may give it a whirl.

James Ikanov - 23-2-2016 at 09:25

Would it be hasty to describe pH (in terms of acidity or how basic something is) as an electrical imbalance?

Or is that rather incorrect?

A tad abstract, but I always end up just seeing reactions as a transfer of energy (electrical or otherwise, and usually electrical) from one atom to another in the form of electrons, and most definitions seem to try to just describe it as a change in hydrogen protons? Is there a practical difference between such an exchange and an electrical charge, in the technical sense of things?

NedsHead - 23-2-2016 at 21:16

Quote: Originally posted by arkoma

tornadoes later today may give it a whirl.

Unintended pun?

j_sum1 - 24-2-2016 at 03:52

Anyone ever use one of these geiger counters that plug into a phone?

Sulaiman - 24-2-2016 at 06:31

A colleage here at work who is into radioactivity who I just asked,
recognised it immediately and said that these are just large area photodiodes with a low gate leakage fet amplifier.
Sounds true as only gamma- and x-rays detected.
Given that, it will probably work as advertised.

The Volatile Chemist - 27-2-2016 at 09:56

Quote: Originally posted by Sulaiman

A colleage here at work who is into radioactivity who I just asked,
recognised it immediately and said that these are just large area photodiodes with a low gate leakage fet amplifier.
Sounds true as only gamma- and x-rays detected.
Given that, it will probably work as advertised.

Cool. That means they'd be mighty cheap to make. I'll have to look to see if there are any schemas available.

Grignard question

SmellNoEvil - 27-2-2016 at 10:46

What would the product of a Grignard Reaction using isopropyl magnesium bromide and acetone be?
There's not much information about the compound available.

[Edited on 27-2-2016 by SmellNoEvil]

The Volatile Chemist - 27-2-2016 at 11:03

Quote: Originally posted by SmellNoEvil

What would the product of a Grignard Reaction using isopropyl magnesium bromide and acetone be?

[Edited on 27-2-2016 by SmellNoEvil]

I hope you don't mind my not using the IUPAC name. In SMILES code:
CC(C)MgBr + CC(=O)C --> CC(C)C(C)(C)OMgBr

When neutralized to the alcohol, you get:
CC(C)C(C)(C)O, or 1,1,2-trimethylpropanol. I think. My prioritizing of groups in IUPAC is bad...

DraconicAcid - 27-2-2016 at 11:09

Quote: Originally posted by The Volatile Chemist

Quote: Originally posted by SmellNoEvil

What would the product of a Grignard Reaction using isopropyl magnesium bromide and acetone be?

[Edited on 27-2-2016 by SmellNoEvil]

2,3-dimethyl-2-butanol

Could this be useful ?

1.6180339 - 27-2-2016 at 18:37

In areas with too much sulfur dioxide, could we[in a industrial process] convert it into sulfur trioxide, make it react with water to create sulfuric acid and then make it react with sucrose to make carbon which could be used for industrial processes?

H2O2

luminouspath - 29-2-2016 at 16:12

I'm planning on concentrating some 12% H2O2 to 30% by removing water under vacuum at ~30c, is this as safe as I think it is?

DubaiAmateurRocketry - 29-2-2016 at 16:33

So i guess if you guys subscribe to some major scientific magazines like, scientific american, or new scientist for example, you might have seen one of the posts like working memory correlates to ability to ignore.

Now sorry if this question sound ignorant, I havent studied much neuroscience, but if I practice my ability to ignore things, such as ignoring a radio while doing something else, would that improve my memory in any way?

Pages: 1 .. 11 12 13 14 15 .. 26