Sciencemadness Discussion Board - The Short Questions Thread (4)

Search before asking questions. It shouldn't be others job to do your own research.
http://www.sciencemadness.org/talk/viewthread.php?tid=12831&...
http://www.sciencemadness.org/talk/viewthread.php?tid=7990
from 5 minutes of searching.

For fuck's sake.
I did search.
I can ask a question if I can't find the answer. I hate people that make a deal out of someone not being able to find an answer. This is called the fucking short question thread for a reason. I didn't go off and make a big deal of it, and I didn't force you to type a response.

[Edited on 19-11-2015 by Camroc37]

[Edited on 19-11-2015 by Camroc37]

gdflp - 18-11-2015 at 18:20

Quote: Originally posted by Camroc37

Well, considering that one of the links I posted was the first result from typing "HEET Methanol site:www.sciencemadness.org" into Google, I can't imagine you searched very thoroughly. This topic has been discussed many times on the forum, its not like the information is inaccessible in the least. If you're unable to find such widely posted information and need someone to search for you, what do you expect will happen if you decide to do more advanced experimenting or work in a professional environment? You certainly are not going to get others to search for you there.

Searching for information is a vital tool in chemistry, rediscovering what is already known and published is a waste of time and money. Even in "The Short Questions Thread", you're still taking the time of others to reply to your post. You're going to need to learn how to search sooner or later, that time might as well be now.

Camroc37 - 18-11-2015 at 18:35

Quote: Originally posted by Camroc37

I do some more complicated things, and it seems like those are easier to find than the simple ones. I can't even find a source of OTC Nitric acid anywhere near me, and I've searched for hours altogether. I figured there would be something on HEET at youtube, but nothing. I read forums but prefer to see people actually doing an experiment.

The Volatile Chemist - 19-11-2015 at 10:32

Sometimes people search for things with SM's search engine. Of all the threads to ask on, this one is fine if someone hasn't UTSE.

Question

TheIdeanator - 22-11-2015 at 11:22

Can I pump gasses into a closed container with a pressure washer to achieve a chamber pressure close to the rated pressure?

I could modify the pump for cooling and I might be able to lubricate the insides, both of which are potential problems that can be addressed.

NexusDNA - 2-12-2015 at 12:21

Hi. does someone know what this glassware is for?

[Edited on 2-12-2015 by NexusDNA]

j_sum1 - 2-12-2015 at 12:27

Looks like a pressure equalising addition funnel. The extra tap at the top is a nice touch although I am not sure how useful it would be most of the time.

DraconicAcid - 2-12-2015 at 12:31

We used to use something like that for solvent distillation. A large RBF below containing the solvent and drying agent, and a condensor above. Open the bottom tap to reflux the solvent over the drying agent, and close it to collect solvent. When you have enough, use a syringe through the upper tap to remove the quantity of solvent needed.

The Volatile Chemist - 2-12-2015 at 12:40

I'm pretty sure that's what it is. Perhaps a combination Strauss and Schlenk flask?

NexusDNA - 2-12-2015 at 12:50

Um, that might be it. I was thinking of a dropping funnel for inert atmosphere. The long neck at the top is intriguing.

The Volatile Chemist - 2-12-2015 at 13:04

What about an inert atmosphere chromatography reservoir?

Yttrium2 - 2-12-2015 at 14:27

What happens when you drink an isoosmatic solution? Will this prevent the leaching of minerals?

Is it harmful to drink saltwater to go to the bathroom?

What would be an example of a semi permeable membrane for an osmotic pressure experiment?

How are most, or all metal ions turned to metals?

We did an experiment in class where we measured the energy required to break 2 of the H's off of H2SO4, what is this energy called? sulfuric is diprotic, quantity of energy required to release second proton, what is this called?

what are all these terms? I feel like I am missing one, there is inversely proportional, linear... ect.. What are the rest?

How come glass is amphorous and not crystalline?

How can lithium be an exception to the octet rule? I read in my book that lithium is an exception, along with beryllium, how are these exceptions?

Why does ozone accelerate the weathering of rubber?

How are heats of vaporization temperature dependent?

Partial pressure and atmospheric pressure change. How does atmospheric pressure affect partial pressure? Can someone explain partial pressure and what it is used for? I am having a hard time understanding it

Why does water efficiently absorb microwaves when microwaves wavelength is long and its energy per photon is lower?

Why does the emission spectra for neon light have so many colored bonds when there are only a few energy levels? - I mean how come when a photon is released from an electron falling from N3 to n1, how come a single color isn't released?

aga - 2-12-2015 at 14:52

Quote: Originally posted by Yttrium2

What happens when you drink an isoosmatic solution? Will this prevent the leaching of minerals?

No.

Quote:

Is it harmful to drink saltwater to go to the bathroom

Depends if there are any Sharks in the saltwater.

Quote:

What would be an example of a semi permeable membrane for an osmotic pressure experiment?

A ceramic Plant Pot.

Quote:

How are most, or all metal ions turned to metals?

Usually the gain of a few electrons.

Quote:

We did an experiment in class where we measured the energy required to break 2 of the H's off of H2SO4, what is this energy called?

Disassociation enthalpy.

Quote:

sulfuric is diprotic, quantity of energy required to release second proton, what is this called?

Disassociation enthalpy.

Quote:

what are all these terms? I feel like I am missing one, there is inversely proportional, linear... ect.. What are the rest?

Fred, Jim and Shelia.
This answer is equally as valid as the question.

Quote:

How come glass is amphorous and not crystalline?

It's still a liquid, just really really slow.

Quote:

How can lithium be an exception to the octet rule? I read in my book that lithium is an exception, along with beryllium, how are these exceptions?

Orbitals. It's all about orbitals not just the rule-of-8.

Quote:

Why does ozone accelerate the weathering of rubber

Oxidation of the organic polymer.
Think about what 'Weathering' means.

Quote:

How are heats of vaporization temperature dependent

Nobody knows apart from zts16 and he's not saying.

Quote:

Partial pressure and atmospheric pressure change. How does atmospheric pressure affect partial pressure? Can someone explain partial pressure and what it is used for? I am having a hard time understanding it

Google Pitot Tube.

Quote:

Why does water efficiently absorb microwaves when microwaves wavelength is long and its energy per photon is lower?

They're not long enough to be outside that absobtion spectrum of water.

Quote:

Why does the emission spectra for neon light have so many colored bonds when there are only a few energy levels? - I mean how come when a photon is released from an electron falling from N3 to n1, how come a single color isn't released?

The same electron can be in one of several energy/spin states.

Check out the Quantum thread.

Please check on self-medication schedules, and if they have been observed or not.

Metacelsus - 2-12-2015 at 15:36

Pitot tubes are for measuring stagnation pressure of a flowing fluid, which is different than partial pressure of a gas.

[Edited on 12-2-2015 by Cheddite Cheese]

aga - 2-12-2015 at 15:42

Ah yes. Quite So.

Please point the questioner in the Correct direction.

Yttrium2 - 2-12-2015 at 15:49

Speaking of the right direction, would you care to elaborate a little on those answers Aga?

Here is a question I found interesting, it says it requires a special procedure. Can someone identify what special procedure they are referring to?

windows 7 print screen

Etaoin Shrdlu - 2-12-2015 at 15:52

Great question. I see no special procedure there.

aga - 2-12-2015 at 16:09

Sideways is not good for me at this time of night.

However ...

it says 3.24g Ti, 5.40g Oxide (presumably Titanium Oxide)

5.40g - 3.24g = 2.16g to account for.

3.24g of Ti @ 47.867g/mol = 0.06768 mol

We're pretty sure it's an Oxide, so what does 0.06768 mol of O weigh ?

1.08g Holy Shit !

Two of those make 2.16g : the number we want !

TiO₂ is likely the right answer,so Titanium Dioxide.

[Edited on 3-12-2015 by aga]

DraconicAcid - 2-12-2015 at 17:38

Quote:

Quote: Originally posted by aga

Quote: Originally posted by Yttrium2

How come glass is amphorous and not crystalline?

It's still a liquid, just really really slow.

No, glass is an amorphous solid. That's practically the definition of a glass.

The glass we normally think of as glass is composed of long-chain polysilicate ions, with branches, paired with a mixture of sodium, potassium, calcium and sometimes other metal cations. When you melt glass, these ions don't flow freely, because they get tangled up in each other (an ordinary liquid could be visualized by a bucket of marbles that can be stirred up. Liquid glass is more like a bucket of cooked spaghetti). When it cools down, the ions can't get past the viscosity of the liquid to form an orderly crystal lattice, they just slow down and stop where they are. So it has the same internal structure as a liquid (but isn't one).

The same is true for things like plastic sulphur and nylon- long molecules which get tangled instead of forming crystals.

Oolong - 8-12-2015 at 07:15

Are there any practical reasons for choosing a multi-neck flask with parallel side necks vs. angled side necks? I noticed from looking at a catalog from a glassware manufacturer that they tend to come with different combinations of joint sizes, and wondered if they were both supposed to be used for different purposes?

Sulaiman - 8-12-2015 at 08:08

I would have at least one of the outer necks at an angle because
I may want a thermometer or air leak or steam inlet in the liquid.

Things I can think of that may go into the necks;
Fractionating column, reflux condenser, thermometer, stirrer, addition funnel, air or steam inlet and probably others.
So only you can answer your question properly.

j_sum1 - 8-12-2015 at 17:26

I was converting some battery gunk -- MnO2 + impurities --> MnSO4 using nurdrage's method.
https://youtu.be/2gXByJkg0iY?t=203

I passed the exhaust gas through a NaOH scrubber to mop up any remaining SO2. My setup, (see below) seemed pretty effective. No sulfurous smell at all (which is what I like in the absence of a fume hood.)
Once the intended reaction was complete, A white crystalline substance began to build up in the scrubber. I wasn't really even thinking about byproducts, but since I have made it I thought I would collect and label. The liquid is still highly alkaline. What I would like to know is whether I have made sodium sufite or sodium bisulfite. I am pretty certain it is sulfite but thought it worthwhile to check.

DraconicAcid - 8-12-2015 at 18:25

If it's highly alkaline, then it would be sodium sulphite. Sodium hydrogen sulphite would be only mildly basic.

j_sum1 - 8-12-2015 at 21:37

Thanks for that DA. Crystals happily drying.

j_sum1 - 12-12-2015 at 03:19

Phenol Red

I recently received an unlabelled vial of a reddish powder. A bit of experimentation and I discovered that it was an acid-base indicator. A bit more careful measurement and I was able to identify it as phenol red. But it doesn't seem like a particularly useful indicator for the things I might use it for. I understand that it has a few applications in biology and is also the indicator often used for swimming pool test kits. I don't have any real use in those two areas. It changes colour over quite a wide range and without a colour matching card seems pretty useless.

So, is there anything interesting that could be done with it? I have a couple of grams.

diddi - 12-12-2015 at 03:26

you could prolly buy a replacement colour card from a pool store for a couple of bucks. the advantage is that it is able differentiate over a large range of pH's with high accuracy rather than just turn at a particular acidity.

j_sum1 - 12-12-2015 at 03:32

Yeah, but if I wanted that, I have some full range universal indicator. And some indicator strips. And a pH meter.

It was the multiplicity of phenol rings that caused me to wonder if something might be made from it.

The Volatile Chemist - 12-12-2015 at 15:33

Clorinate it? I have no clue how chlorinated you could get it, but if you took a sample and passed chlorine through it, I'd assume you could at least get that central carbon to a tertiary chloride, and turn the non-phenyl ring into a phenyl ring. Is this just spitballing? I have no clue if it'd work. Versuchschemie.de had a bit of dye chem on it.

Two quick questions:
1. If you add boric acid to 'bicarb, do you get sodium borate or tetraborate? Is the resulting compound capable of precipitating Copper(II) borate from a soluble Copper(II) salt?
2. What's the best way to purify HCl with lots of Iron(III) Chloride in it? I've seen the procedure which involves placing a container with the HCl and a container with water in it in a larger container and letting it sit there. I have no suitable large container.

Thanks for any answers,

[Edited on 12-12-2015 by The Volatile Chemist]

gdflp - 12-12-2015 at 15:52

The central carbon on that class of dyes will not halogenate. Instead, you will get either di- or tetra- halo aromatic substitution, depending on whether or not an excess of halogen is used. In the case of phenol red, bromination with bromine in acetic acid will yield bromophenol blue.(See Vogel 3rd, pg. 990)

hyfalcon - 12-12-2015 at 16:09

Bert, I have a question for you. How do you negate all the static build up in the air this time of year? You don't just avoid fireworking I'm sure. When I run my hand down my dogs back and it crackles all the way down, I know not to touch anything that might not like static discharge.

The Volatile Chemist - 14-12-2015 at 15:06

http://www.mcmaster.com/#standard-steel-tubing/=10bn3ld

The central carbon on that class of dyes will not halogenate. Instead, you will get either di- or tetra- halo aromatic substitution, depending on whether or not an excess of halogen is used. In the case of phenol red, bromination with bromine in acetic acid will yield bromophenol blue.(See Vogel 3rd, pg. 990)

Makes sense. Interesting. If I ever get any bromine and phenol red, I'll have to give it a try. Perhaps halogenation with chlorine and bromine would be good projects.

CuReUS - 17-12-2015 at 09:38

Is it possible to make a grignard reagent from a halo nitroarene,say 3-bromonitrobenzene ?

Crowfjord - 17-12-2015 at 10:35

Grignards react with aromatic and aliphatic nitro compounds to give the disubstituted hydroxylamines. See for example J. Chem. Soc. Perkin Trans. (1990) 2133-2138. 3-bromonitrobenzene would probably polymerize with the addition of magnesium.

Nitric Acid Safety,Quick Question.

CitricAcid - 17-12-2015 at 15:56

I have a quick question about safety regarding nitric acid:Why is it classed as a level 4 health hazard on the MSDS and the NFPA 704? As far as I know,getting it on the skin won't kill you unless you spill a whole beaker and all of it lands on your skin.

Agari - 17-12-2015 at 16:13

Skin contact isn't what will kill you,but rather inhalation. Inhaling nitric acid vapor will not only release toxic nitrogen dioxide gas directly into your lungs,but will also paralyze the diaphragm and make it impossible to breathe. In fact, it is produced by the burning of nitromethane,which is used as a booster in racing cars,drivers often have to wear face masks to avoid inhalation of the toxic vapors.

The Garbage Guardian - 18-12-2015 at 21:13

Hello, I'm new here, and am trying to build the sodium cell that len made. Does anyone know where to get the thick steel tube needed? All pipe from hardware store is painted, galvanized, too small.

arkoma - 20-12-2015 at 07:55

I have 80ml piranha (60ml H2SO4, 20ml 12%h2o2) that I've used to remove red wine stubborns out of my 1l RBF. I've been doing crude KOH extractions from oak ashes in my backyard. Surely some of my leachate from the ashes would neutralize it safely? No heavy metals or other nasties in it. Arkansas is too pretty to pollute..........

JJay - 20-12-2015 at 08:15

It should be safe to pour out if you dilute it heavily.

CuReUS - 20-12-2015 at 08:22

Quote: Originally posted by Crowfjord

Grignards react with aromatic and aliphatic nitro compounds to give the disubstituted hydroxylamines. 3-bromonitrobenzene would probably polymerize with the addition of magnesium.

what if you reacted 3-nitrobenzaldehyde with R-MgX ? would the grignard attack the carbonyl group to give the alcohol.?
In morrison and boyd,it is written that grignard reactions cannot be done on nitro compounds as the nitro group will oxidise the grignard reagent .

elementcollector1 - 20-12-2015 at 09:24

Quote: Originally posted by The Garbage Guardian

Hello, I'm new here, and am trying to build the sodium cell that len made. Does anyone know where to get the thick steel tube needed? All pipe from hardware store is painted, galvanized, too small.

A different hardware store.
Amazon.
EBay?

The_Davster - 20-12-2015 at 09:47

Quote: Originally posted by The Garbage Guardian

Hello, I'm new here, and am trying to build the sodium cell that len made. Does anyone know where to get the thick steel tube needed? All pipe from hardware store is painted, galvanized, too small.

arkoma - 20-12-2015 at 10:20

this would be a SECONDARY alcohol? it's honokiol, from magnolia tree bark.

gdflp - 20-12-2015 at 10:42

No, since the hydroxyl groups are connected to the aromatic rings, they behave very differently than they would if they were connected to a straight sp3 carbon chain. Short explanation : this is due to the free circulation of electrons in the conjugated pi system greatly changing the reactivity. They have their own nomenclature and are called <b>aryl</b> alcohols.

Crowfjord - 20-12-2015 at 12:16

Quote: Originally posted by CuReUS

Are benzaldehydes more easily reduced than aromatic nitro groups? If so, that might work to give the alcohol, as long as the nitrobenzaldehyde is kept in excess. I imagine that in some cases the nitro would oxidize the grignard reagent rather than form a C-N bond. In that case, wouldn't the nitro be reduced to a hydroxyl amine?

The_Davster - 20-12-2015 at 13:08

If you take a nitro group and react with with a grignard of the XMgNHR type you get the below

R-NO2 + XMgNHR' --> R-N(O)=N-R' very useful for energetics synthesis...

CuReUS - 21-12-2015 at 04:59

Quote: Originally posted by The_Davster

If you take a nitro group and react with with a grignard of the XMgNHR type

won't the H of the XMgNHR destroy the grignard reagent formed since its acidic ? I think you meant XMgN(R)₂.

PHILOU Zrealone - 21-12-2015 at 05:19

Quote: Originally posted by gluon47

Can nitric acid be feasibly produced via the reaction of potassium nitrate and hydrochloric acid? I've seen many vids of people making it with sulphuric acid and potassium nitrate but none using hydrochloric acid.

In principle it seems a good idea because HCl is a much stronger acid than HNO3...

But practically it is not a good idea because:
-HCl is much more volatile than HNO3
-HCl reacts with HNO3 to form nitrosyl chloride O=N-Cl (see aqua regia) and thus the mixes of HCl/HNO3, NaCl/HNO3 or NaNO3/HCl will be able to dissolve nearly all metals ... even nobles ones (gold, platine, rhodium,...)

PHILOU Zrealone - 21-12-2015 at 05:26

Quote: Originally posted by CuReUS

Quote: Originally posted by The_Davster

If you take a nitro group and react with with a grignard of the XMgNHR type

won't the H of the XMgNHR destroy the grignard reagent formed since its acidic ? I think you meant XMgN(R)₂.

@CuReUS,
Why would XMgNH-R be acidic?
If R is alkylic, I suspect it wouldn't be (well everything has something more acid or basic than itself that would make it look like an acid or a base but that's another debate --> solvent effect).
Without knowing what R is hard to tell!

Also if it was acidic would'nt it form (XMg)2N-R?

PHILOU Zrealone - 21-12-2015 at 05:28

Quote: Originally posted by The_Davster

If you take a nitro group and react with with a grignard of the XMgNHR type you get the below

R-NO2 + XMgNHR' --> R-N(O)=N-R' very useful for energetics synthesis...

@The_Davster,
Do you have a reference, link or document for me?
That reaction is very interesting for the energetic materials field ... and I'm passionnate about those...

Wolff-Kishner reduction.

CitricAcid - 21-12-2015 at 10:11

I found quite an interesting process on the Internet called the Wolff-Kishner Reduction,which goes as follows:

How are the two nitrogen atoms in the intermediate removed to give the final methylene group?

Does it mean that propane/butane can be synthesized from Acetone and MEK respectively?

[Edited on 21-12-2015 by CitricAcid]

User123 - 21-12-2015 at 10:36

The scheme is incomplete. It uses a strong base such as sodium hydroxide to abstract the hydrogens on the outer nitrogen atom and form first a double, then a triple bond between the two nitrogens. When the triple bond forms the nitrogen-carbon bond breaks and (I don't know whether 'formally' or in-reality) a carbanion is formed which abstracts a proton from the solvent (I think that ethylene glycol is used, but I'm not sure).

Yes, you can make propane and butane. It is a robust reaction, with good yields, but it can only be used on substances that can withstand the harsh conditions, and is not a very good general reaction.

[Edited on 21-12-2015 by User123]

CitricAcid - 21-12-2015 at 10:45

Quote: Originally posted by User123

The scheme is incomplete. It uses a strong base such as sodium hydroxide to abstract the hydrogens on the outer nitrogen atom and form first a double, then a triple bond between the two nitrogens. When the triple bond forms the nitrogen-carbon bond breaks and (I don't know whether 'formally' or in-reality) a carbanion is formed which abstracts a proton from the solvent (I think that ethylene glycol is used, but I'm not sure).

Yes, you can make propane and butane. It is a robust reaction, with good yields, but it can only be used on substances that can withstand the harsh conditions, and is not a very good general reaction.

[Edited on 21-12-2015 by User123]

Do you mind giving a theoretical setup to make your explanation more understandable in practice? Suppose that Acetone is used to make propane,how will the entire setup work/look like?

[Edited on 21-12-2015 by CitricAcid]

User123 - 21-12-2015 at 11:07

You'd just have a flask with acetone hydrazone dissolved in ethylene glycol. To that you would add NaOH or KOH, heat it to 180C or so, and propane would come flying out of the top!

Is that what you mean?

If you had a non-trivial substrate -- say the product was n-hexylbenzene -- then it would be dissolved in the ethylene glycol, and you would let it cool, add water, then extract the n-hexylbenzene with a solvent.

[Edited on 21-12-2015 by User123]

Hydrazine

CitricAcid - 21-12-2015 at 12:17

Is there any way to isolate hydrazine from mixing bleach and household ammonia without adding sulfuric acid? What I mean is:Is there any way to separate hydrazine from everything else that is formed when mixing bleach and ammonia? Can it be separated via sep funnel?

[Edited on 22-12-2015 by CitricAcid]

Iodine

CitricAcid - 21-12-2015 at 19:07

Is there any source that sells iodine crystals to individuals?

Dr.Bob - 21-12-2015 at 19:14

Ebay has a few sources for 50g/$10.

CitricAcid - 21-12-2015 at 19:44

Since that was a very quick thread,I'll ask another question: Is there any good source of phosphorus? I intend to use it to make PBr3 for use in brominating alcohols.

Agari - 21-12-2015 at 19:56

Since that was a very quick thread,I'll ask another question: Is there any good source of phosphorus? I intend to use it to make PBr3 for use in brominating alcohols.

Onyxmet.com sells phosphorus, J_Sum1 claims to have bought from them more or less frequently,you can ask him if you have any questions about it.

Edit:I doubt you can cleanly separate hydrazine from solution,the densities of household bleach,ammonia,and hydrazine are very similar,and it is also miscible in water,so you will likely need to chemically separate them.

[Edited on 22-12-2015 by Agari]

CitricAcid - 21-12-2015 at 20:00

Back to my original hydrazine question: In addition to isolating it without converting it to its salt form,is there any combination of solvents that can be used to extract it from solution?

arkoma - 21-12-2015 at 21:11

Benzyl alcohol, Cyclohexanol--KCr2O7 and KMnO4 kin possession. Expected products from oxidations?

Oscilllator - 21-12-2015 at 21:24

Benzyl alcohol, Cyclohexanol--KCr2O7 and KMnO4 kin possession. Expected products from oxidations?

My first year chemistry tells me alcohols get oxidised first to aldehydes then carboxylic acids. Because these are such strong oxidisers however you almost certainly won't get any aldehydes, and because this is the real world you might well also get black goo as the primary product.
pH will also play a role in the oxidations, but that's above my skill level.

I suggest smelling the reaction mixture in the benzyl alcohol experiment. Strong smell of vomit = you have produces benzoic acid.

Zyklon-A - 21-12-2015 at 21:27

Citric acid, I think you may be confused.
You don't need red P and iodine plus the Wolff-Kishner to reduce epinephrine, one is enough!
If your meth lab can't make hydrazine, you can use the Clemmensen reduction. All you need is Zn/Hg, HCl and ETOH.
But first you must oxidize epinephrine to its ketone.
If you're still having trouble I've got a friend at the DEA who will be glad to 'wrap things up'!
Or do you really want to waste acetone and hydrazine to make propane? Really?

Texium - 21-12-2015 at 21:29

Benzyl alcohol would be oxidized as Oscilllator describes, first to benzaldehyde and then to benzoic acid. Though I'm pretty sure benzoic acid doesn't have much of an odor, so I don't know where the vomit thing is coming from.
Cyclohexanol, however, is a secondary alcohol, so it will be oxidized to a ketone- cyclohexanone- and no further.

Oscilllator - 21-12-2015 at 22:03

Quote: Originally posted by zts16

Benzyl alcohol would be oxidized as Oscilllator describes, first to benzaldehyde and then to benzoic acid. Though I'm pretty sure benzoic acid doesn't have much of an odor, so I don't know where the vomit thing is coming from.
Cyclohexanol, however, is a secondary alcohol, so it will be oxidized to a ketone- cyclohexanone- and no further.

woopsie, I thought he meant butanoic acid. See, this is what happens when you don't do chemistry for a while - stay away from not doing chemistry kids!

DraconicAcid - 21-12-2015 at 22:15

Benzyl alcohol, Cyclohexanol--KCr2O7 and KMnO4 kin possession. Expected products from oxidations?

If you oxidize cyclohexanol with permanganate, you will probably get adipic acid.

Texium - 21-12-2015 at 22:19

Quote: Originally posted by DraconicAcid

Benzyl alcohol, Cyclohexanol--KCr2O7 and KMnO4 kin possession. Expected products from oxidations?

If you oxidize cyclohexanol with permanganate, you will probably get adipic acid.

Oh sure enough, I forgot about that possibility. Jones oxidation with dichromate should still yield cyclohexanone though.

Zyklon-A - 21-12-2015 at 22:55

I'll add a little to the correct answers above.
1)
Either oxidizer will turn benzyl alcohol to benzoic acid (with good yields). You can stop the oxidation at benzaldhyde by excluding water (use pyridinium chlorochromate)
2)
Cr(VI) will oxidize cyclohexanol to cyclohexanone. Mn(VII) will do that too... then it will likely break the carbonyl carbon-alpha carbon bond, eventually yielding hexanedioic acid! (Well really K/Na hexanediate as the reaction requires a base.)

Deathunter88 - 23-12-2015 at 06:31

Are there any soluble barium compounds that can be used to test for the sulphate ion other than barium nitrate and barium chloride?

I ask because I just recently found out that barium chloride is listed as an "extremely toxic" chemical in China and thus illegal for an individual to possess. Barium nitrate on the other hand is listed as an explosives precursor and also illegal for the individual to own.

OR if no such compound of barium exists then suggestions of any other compounds that can be used to identify the existence of sulphate ion in solution would be welcomed.

UC235 - 23-12-2015 at 06:46

Quote: Originally posted by Deathunter88

Are there any soluble barium compounds that can be used to test for the sulphate ion other than barium nitrate and barium chloride?

I ask because I just recently found out that barium chloride is listed as an "extremely toxic" chemical in China and thus illegal for an individual to possess. Barium nitrate on the other hand is listed as an explosives precursor and also illegal for the individual to own.

OR if no such compound of barium exists then suggestions of any other compounds that can be used to identify the existence of sulphate ion in solution would be welcomed.

The barium salts are considered extremely toxic because of the barium. Changing the anion won't change anything, though it may do so regulation-wise. Is BaCO3 similarly regulated? You can just dissolve it in HCl and filter any unreactive goop off to make a BaCl2 solution.

Strontium salts also produce a precipitate with sulfate and are far less toxic, but are considerably less sensitive.

[Edited on 23-12-2015 by UC235]

What am I doing wrong?

BryceFitz - 23-12-2015 at 06:56

I am trying to make a rocket similar to an Estes rocket, but a little more powerful. So far in my project, I have made and tweaked small 25 gram samples in paper casings. My best results thus far are from 1 gram sulphur, 5 grams aluminum powder, 16 grams ammonium nitrate, and 3 grams silicone caulk. I have compacted the fuel in a casing with a hammer and drilled a hole through a clay nozzle and fuel. I have then put a sparkler in through the nozzle and lit the end as a fuse, and my best result was sparks and flame shooting out the back at least 5 feet, yet the rocket produces little to no thrust. Can anyone tell me why this is, or what I could do to improve my rocket?

Fulmen - 23-12-2015 at 07:04

First off you're not providing a descriptive subject. That alone should be enough to have the post deleted in my opinion. Other than that, use potassium nitrate. Ammonium nitrate is not well suited for simple rockets.

arkoma - 23-12-2015 at 07:11

^^^as usual, great answers. Gonna do any of these OUTSIDE. With my kinda luck, if it can burst into flames, it will. My rooster might just get startled today.

PHILOU Zrealone - 23-12-2015 at 12:46

Quote: Originally posted by Deathunter88

Ba acetate
Ba hydroxyde
Ba perchlorate

Formaldehyde

CitricAcid - 23-12-2015 at 20:24

Is there any way to isolate formaldehyde from products that contain it or to synthesize it?I heard about the catalytic oxidation of methanol,but I think there is too much of a risk of igniting the formaldehyde/methanol,so is there any other way to synthesize it?

Green nitric acid

idrbur - 23-12-2015 at 21:29

Yesterday i was trying to concentrate nitric acid.

My plan was to bubble NO2 through dilute nitric acid because NO2 hydrolises in water to give HNO3 and HNO2.

but when i bubble NO2 nitric acid turned dark green. Anybody knows why this happend.

Texium - 23-12-2015 at 21:39

Is there any way to isolate formaldehyde from products that contain it or to synthesize it?I heard about the catalytic oxidation of methanol,but I think there is too much of a risk of igniting the formaldehyde/methanol,so is there any other way to synthesize it?

There are many threads about synthesis of formaldehyde, as well as plenty of information elsewhere on the internet... search and ye shall find.

woelen - 24-12-2015 at 03:54

Quote: Originally posted by idrbur

Yesterday i was trying to concentrate nitric acid.

My plan was to bubble NO2 through dilute nitric acid because NO2 hydrolises in water to give HNO3 and HNO2.

but when i bubble NO2 nitric acid turned dark green. Anybody knows why this happend.

In one of the other posts I read that you bubbled NO2 through 60% HNO3. This is not dilute anymore. What happens is formation of HNO3 and NO. With more NO2 you get N2O3, which is deep blue. Together with the dark brown of NO2 you end up with a green color. Your acid becomes contaminated with N2O3. You can remove that by bubbling a lot of air through the acid.

This effect can also be observed when dissolving a metal, giving colorless metal ions. E.g. dissolve some mercury, bismuth or lead in conc. nitric acid. You'll see that the liquid turns green. This is caused by formation of a mix of NO and NO2 when the metal dissolves. On dilution with water, this color disappears, the N2O3 then is hydrolyzed and bubbles of NO escape from the liquid and the liquid itself becomes colorless.

DraconicAcid - 24-12-2015 at 04:04

Quote: Originally posted by woelen

What happens is formation of HNO3 and NO. With more NO2 you get N2O3, which is deep blue. Together with the dark brown of NO2 you end up with a green color.

Don't you only get N2O3 at low temperatures? I remember holding a chunk of dry ice above a reaction mixture of copper and nitric acid, and getting solid blue condensing on the ice.

woelen - 24-12-2015 at 05:22

In aqueous solution you can have it at room temperature as well. It is quite stable in conc. HNO3, in water it slowly decomposes.

A nice experiment is adding a few drops of a concentrated solution of NaNO2 to dilute acid at room temperature (e.g. 10% H2SO4). You get bubbles of NO/NO2, but the solution turns blue as well. Not really deep blue, but easily observable like a fairly dilute solution of CuSO4 in water. This is N2O3. On standing it slowly disappears and the liquid becomes colorless. If the acid is colder, then the color persists for a longer time.

PHILOU Zrealone - 24-12-2015 at 05:48

Is there any way to isolate hydrazine from mixing bleach and household ammonia without adding sulfuric acid? What I mean is:Is there any way to separate hydrazine from everything else that is formed when mixing bleach and ammonia? Can it be separated via sep funnel?

[Edited on 22-12-2015 by CitricAcid]

Back to my original hydrazine question: In addition to isolating it without converting it to its salt form,is there any combination of solvents that can be used to extract it from solution?

Methylethylketone azine...is a good way to go
(CH3-CH2-)(CH3-)C=N-N=C(-CH2-CH3)(-CH3)

Addition of Ni(NO3)2 in the wish to precipitate Ni(N2H4)3(NO3)2 (nickel nitrate(II) tris-hydrazino complex) doesn't work!

The_Davster - 24-12-2015 at 15:42

Quote: Originally posted by PHILOU Zrealone

@The_Davster,
Do you have a reference, link or document for me?
That reaction is very interesting for the energetic materials field ... and I'm passionnate about those...

t-Butyl azoxy next to an amine on an aromatic system.....nitrate and the nitramine cyclizes with the tBu azoxy giving a 1,2,3,4-tetrazine-1,3-dioxide. Sexy molecules.

Easier method is to take R-N=O and react with tBuNBr2 (Horrible smell

) giving R-N(O)=N-tBu. Those working with these type of molecules seem to have abandoned the grignard for the nitroso route.

Attachment: how to make THE GRIGNARD.pdf (332kB)
This file has been downloaded 1237 times

Flourine

Maker - 26-12-2015 at 17:22

I'm aware of the dangers of fluorine, but I was thinking; If someone wanted to do some flourine chemistry, would it be possible to use PTFE plastic or plumbers tape and extract it from that? It's just idle curiosity, I have no current plans to play with anything this reactive.

Bit late, but Merry Christmas

j_sum1 - 26-12-2015 at 18:08

Hey, zts. I had just composed a reply and lost it because the thread was merged when I submitted. Your efficiency is spectacular.

@maker
firstly, "flourine", I presume is a derivative of flour and probably harmless.

Secondly, in case no one has done so already, welcome to SM. Stick around. Read the faq. Learn some stuff -- there is a wealth of great knowledge here.

Thirdly, addressing your question:
Fluorine is nasty stuff. Few have a legitimate reason to work with it and those that do have specially-equipped labs. Those without the technical equipment and proper knowledge tend to have a lower life expectancy. Fluorine killed a number of people on the way to being isolated. One of the issues is the fact that it is so oxidising that it is next to impossible to contain it in anything. Another issue is the tendency to form HF and kill the experimenter. The difficulties ramp up from there.

PTFE is probably the compound that contains the most fluorine on a mass basis that you are ever going to encounter. It is quite ironic that it is so safe. There is a cool experiment that you can do with it if you have some powdered aluminium or Mg. (The powder must be fine however.) Dust some metal powder onto some plumbers' tape and hit it with a flame. You get a nice thermite-style reaction that is reasonably impressive. You do need to do this outside. Avoid breathing any fumes because some of the byproducts are toxic. It is reasonably spectacular and simple to do.

What's this white growth in my Copper Acetate solution?

esgeroth - 1-1-2016 at 16:17

I just made some Copper Acetate from some copper wires to grow crystals from. I dissolved the wires in vinegar and hydrogen peroxide.
As the copper acetate solution evaporates, dark colored crystals start growing at the bottom. After a few days I also start seeing a white substance growing on my crystals.
Does anyone know what this is? And how do I prevent it from growing so I can get some nice clean crystals?

DraconicAcid - 1-1-2016 at 16:26

Basic copper(II) acetate. Add more acetic acid.

Stannous chloride

cblownglass - 1-1-2016 at 19:18

I use stannous chloride in my glass blowing operation to iridize my glass. After spraying I try to recycle the residue but some contaminants are present so the contaminants slowly build up and affect the quality of the iridescence .I put the sludge or residue in a crock pot and cooked off all of the liquid but got a grayish crystalline rock.I have re-dissolved the rock but got a dark brown liquid with a lot of sludge on the bottom of the jar.I drained to brown liquid from the sludge I think this residue is my earlier contaminates . The brown liquid fumes ok but I would like to try and get back to a clear crystal stannous form that I started with .Any suggestions.

Texium - 1-1-2016 at 20:53

Quote: Originally posted by j_sum1

Hey, zts. I had just composed a reply and lost it because the thread was merged when I submitted. Your efficiency is spectacular.

Oops, sorry about that!

arkoma - 2-1-2016 at 20:28

Quote: Originally posted by DraconicAcid

Basic copper(II) acetate. Add more acetic acid.

Oh man. This has actually been a "burning question" of mine. "Basic" Copper Acetate?

Valency of manganese

Romix - 3-1-2016 at 18:39

Solution were yellow, precipitated hydroxide, light brown lumps.
Decomposed to oxide, it got darker, and lost weight.
What valency of Mn is this?

elementcollector1 - 3-1-2016 at 18:47

Likely IV, at this point.

j_sum1 - 5-1-2016 at 03:46

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?

Hydrogen peroxide extraction from sodium persulfate

The Chemistry Kingdom - 6-1-2016 at 15:25

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

The Volatile Chemist - 6-1-2016 at 15:48