Orange-limonene reaction and sulfuric acid, color chemistry

I've bought orange oil from the store, "Howard Orange Oil, Wood polish" expecting it to be a cheap source of D-limonene. I'm a beginner at Chemistry, and would like some opinions about my experiment and conclusions.

The Howard bottle says it contains petrolium distillates ... but D-limonene is likely cheaper to get from Oranges, and it does smell like Oranges and not so much lemon.
When I look at the liquid, it has an orange color (like the rhind of an Orange.)

However, when I look up D-limonene, the terpene (alkene) is stated to be "colorless."
http://www.sciencemadness.org/smwiki/index.php/Limonene

So, I assume there is some kind of impurity in Orange oil that gives it the Orange color.
But I'm curious about the reactivity of D-limonene to strong acids/bases etc.

When I was studying low density bi-layers for an experiment with Iron Pyrite (FeS2), I was told that perhaps limonene being an aromatic alkene was reacting with my non-aquatic ionic solvents;.

@clearly_not_atara
https://www.sciencemadness.org/whisper/viewthread.php?tid=15...

So I wanted to see how reactive it was compared to kerosine.
All alkanes in in Kerosine, like Nonane-Decane, are also clear. So it would be hard to tell alkanes added to orange oil apart from D-limonene. The Odor of oranges is there, though, so I'm pretty sure there is D-limonene in Howard's. The same's true with "goo be gone." But that could be a coloring gimmick ...

So, I decided to try an experiment. Sulfuric acid, when refluxed, eventually becomes strong enough (looses water) to even strip hydrogen off of alkanes. But, if it's mixed with Iron Pyrite (fools gold), the Pyrite should dissolve into solution before the acid gets that strong. ( Intuitive idea. ) So, I planned to use pyrite to weaken the ultimate concentration the sulfuric acid can reach.

If I mix pyrite with hot HCL, I smell rotten eggs. However, when I mix it with H2SO4 (aq) bought from Napa for batteries, the acid turns reddish-orange (even with no D-limonene mixed in). No scent of rotten eggs is smelled. So, I *think* that very little free H2-S is released from Sulfuric Acid boiling, and most H2-S acid that exists is being kept in solution as an ion. ( Or else, the pyrite is dissolving as FeS or FeS2, and no H2-S or sulfate ion is being produced in the first place. In any event, I added a little citric acid to make sure it favors the dissolution of iron-sulfide as much as possible to keep the acid as weak as possible while building up in concentration.

Then I pour Orange oil on top of the acid, and let it reflux at about 104 to 110C. If oxygen is allowed in the bottle, some of the orange oil will blacken slowly on top. If not, what happens is immediately (even without fools gold) the orange color of the Orange oil fades a little bit, and the sulfuric acid becomes very orange. Adding fools gold only darkens it more with time and heating .....

So, I think whatever colors Orange oil, Orange, is very soluble in acids.

I know from patents that sulfuric acid will turn a-pinene into an alcohol of some kind (from turpentine) which has an orangish-resin color. So, I reasoned that the same kind of chemical reaction is likely to occur with D-limonene and acid; I would except it to create an OH radical somehow ... if it's not done so fast as to "burn" the Orange oil.

But, what I'm seeing in the flask is that the quantity of D-limonene is staying essentially constant but the Orange color is disappearing. The liquid on top of the bi-layer is becoming more and more clear, and still floats on top of the concentrating sulfuric acid.

The following flask has been run twice with the same orange oil, and the Sulfuric acid replaced. The first time I ran it was for two hours, and a short reflux column (3 inches).
Absolutely no burning or blackening was seen. The second time I ran it with a longer reflux column for 12 hours. The H2SO4 was not reduced in volume significantly, but only a very tiny amount of brown material stuck to the glass in a ring at the air-oil interface. When I removed the reflux column, I could see a white steam leave the bottle with the smell of citrus (not orange, specifically) and I allowed it to boil for another two hours. The H2SO4 (battery acid from Napa), decreased in volume by about half and became much darker orange. The Orange oil became a pale yellow (hard to see in the photo) and a lot more blackening showed up above the oil.

So, qualititaviely, I am concluding that the D-limonene is not likely reacting with the strong sulfuric acid and producing an alcohol or resin, like a-pinene is supposed to do.
But rather, something in the oil is burning in air ...

If I repeat the experiment with alkanes, (clear), about the same happens. Some slight blackening occurs in a ring at the air-kerosine layer after 12 hours of refluxing, but no noticeable volume change happens.

With D-limonene, or A-Pinene, is it not the double bond of at least one carbon atom which makes it an alkene, rather than a saturated alkane?

If the double bond makes it an aromatic hydrocarbon, wouldn't that also suggest the double bonded carbon is the location where lysis, or conversion to alcohol/resin would be initiated most easily ?

Am I correct in assuming no significant D-limonene reaction happened, since an alcohol or resin would be soluble in an acid (making an ester.) but no significant volume change means no significant amount of D-limonene reacted with H2SO4?

Also, in water ... ligands usually give the liquid the color. In oil, is that also the same ?
Is the orange color a complex of something, and therefore more likely to be chemically reactive than a hydrophobic oil would be?




[Edited on 27-6-2020 by semiconductive]

I'm an amateur, without a whole lot of reagent grade chemicals around.
I'm looking for qualitative tests and speculation (likelihood.)

I thought aromatics smelled, and aliaphatics didn't.
Orange is a pretty strong odor, though citrus/lemon is very faint.

Does you mean both isomers of Limonene are aliaphatics?

Cymene has more double carbon bonds than Limonene, so I guess that alternating set of single and double carbon bonds in the carbon ring is what clearly makes Cymene aromatic.

But when I compare that to saturated alkanes, eg: Kerosine -- doesn't have any double bonds ... and pretty much are odorless.

So, in an impure limonene sample (likely D-Isomer/enantiomer is orange smell ) ---
What likely increases the chemical reactivity enough that I smell Orange? (I mean, it could just be orange peel extract for all I know. )

Isn't odor in the nose because of chemical reactivity?
It seems backward that aromatics would have less chemical reactivity than things that don't smell.

I see the definition of huckel's rule, but I don't understand the subtlety well.

Turpines definitely smell, and both Cymene and Limonene (at least D) are supposed to smell.




[Edited on 28-6-2020 by semiconductive]

[Edited on 28-6-2020 by semiconductive]

Quote: Originally posted by DraconicAcid

Non-aromatic compounds aren't odourless- they just lacked the characteristic odour that the first aromatic compounds to be discovered had. The chemical meaning of "aromatic" is now completely divorced from its original meaning of smelly.

I see, I did mess up D and L with R and S. Dextro, Levulo, are latin for Right and Left handed.
Thank you for pointing that out. I didn't check the abbreviations....

But, how would a straight chain of Carbons with hydrogen on all sides ... hexane ... as an alkane, be able to have an isomer without forming a ring structure? It seems to me the carbons with two or three hydrogens each would be free to rotate; and therefore, there is no definite chirality to a straight chain hydocarbon. It looks amorphous to me or unable to form a chirality.

There's no obvious spiraling in it, like in an amino acid.

Good. That's what interests me.... when they "touch" in some way, the energy triggers a chemical reaction inside the nerve cell. So, at very least ... an electron has to be "excited" to a higher orbital, to trigger a chemical reaction.
Electricity, is what I'm good at -- I'm an electrical engineer.

It's not that I don't understand that molecules "fit" shape wise, and touch, and that can cause physical motion. There are many physical chemistry effects like sugar dissolving in water, and sugar-water drying out to release sugar crystals again. No chemical change occurs. But at the same time, I tend to think that many reversible chemical reactions probably happened to the sugar when it dissolved in water. For example, alcohol, or -OH radicals, can often release (temporarily) a hydrogen atom or OH; but on average, the ionization doesn't cause a permanent change to the substance (alcohol.)
Sugars seem to have a similar -OH chemical in many cases, and are probably similar to alcohols chemically. Something I will look into more as I have time.

I was simply not aware of a chemical reaction being *triggered* in the nose cells without some kind of reaction happening. I will leave it at that, and study the issue online in the 'library'. Thanks for your time.

Here's some photos, and they're limited.
I'm not sure what's with my camera today ... but when I upload pictures to my computer, many of the pictures don't open correctly and have to be cropped.

After running the previous experiment, I chilled the contents in a freezer over the weekend. You can see darker matter stuck to the wall of the empty vial, which I moved the liquid to the other vial. The amount of loss after freezing is about the amount of citric acid I put in at the start of the experiment. The solution is very clear, with no burnt matter in it.



This is a picture of the electrochemistry cell I use to test conductivity and attempt plating. Normally, the sand in the bottom of the glass cell is fools gold (Iron Pyrite) color; but my last experiment I bought sulfur (for the first time ever); I wanted to see if it would dissolve under electrical potential into sulfuric acid. I never had sulfur (straight) in the past, even though the DHS claims I told them I put "sulfur" in my fishtank... SO4 ... Sulfur ... yeah, they're not wrong ... but not right, either. Anyhow, in this experiment ... the sulfur actually hardened the fools gold together from a powder into a solid during the electrolysis experiment. It's hard as a rock, now. Oddly enough, the pyrite has lost it's gold tone after being electrolyzed with elemental sulfur S8.



This is the electrolysis cell, being set up to see if the solution I processed at start of this thread is conductive. There is a steel washer in the mix, and a graphite electrode (AA battery cell.) The electrode is contaminated with a small amount of Manganese, but after treateing with HCl they are pretty inert. Unfortunately, in the last experiment with sulfuric acid and elemental sulfur, for the first time almost half the carbon electrode dissolved into solution and immediately re-precipitated out on the electrode again with Iron Pyrite cementing the carbon dust together. Oddly enough, Iron Pyrite does not like to electroplate out on the Cathode (- electrode); but actually likes to form on an anode or electro-positive metal -- like aluminum. Put an aluminum wire in the liquid ... and it will coat with Iron Pyrite.

There are three electrodes in the cell; a positive pulsing carbon electrode; a neutral Iron Pyrite electrode; and a negative pulsing steel washer used as a cathode.
When I turned the power on, 1mA (practically nothing) flowed at 172V of potential.
Note, the power is pulsed DC to prevent current from going from carbon electrode directly to steel washer. So, the Iron Pyrite alternately receives +flow electricty from the anode, and then during a different cycle returns +electric charge to the washer/cathode.

so, the liquid does not have many ions in it after being concentrated.
However, when I reversed the polarity making the pyrite positively charged, and the carbon rod neutral; THEN 50mA began flowing. So, iron pyrite likes to ionize the fluid with positively charged atoms. Probably iron ions... but I'll have to wait and see what plates out.




This is the cathode (plating target) from the last sulfur/Sulfuric acid experiments. The small washer was the initial test target, and was plated with 10mA 3V for about an hour. It has a golden film on it (hard to see) which is iron pyrite. It's a semiconductor and tests positive for point contact diode tests. (Schottky).

The larger washer was left in the plating solution for 3 days at 70mA (~3V) and the part that is most brightly silvery was in the electrolyte. The part that is duller, above, was not in the electrolyte and was that color from the previous experiment. A silvery metal, possibly nickel contamination in the pyrite or zinc, or else just an unusually bright deposit of iron (This is not what Iron normally looks like after plating) is the only thing that remained. Pyrite did not plate out after elemental sulfur equilibriated with the solution, unlike what it did when sulfuric acid was mostly pure at the start of the experiment with citric acid only.



Fishtanks ... ammonia ... and history:
Fish "pee" urea out their gills, as do shrimp. Sulfur bacteria (or possibly archaea) can take CaSO4 and turn it into FeS2, by using using urea in the water as "fuel." Read up on the sulfur cycle if you want to understand why most swamps smell like sulfuric acid and have dark acidic greenish-soil.

The fishtank experiment I did years ago used iron nails and plaster to form a "fake" swamp bed that was trying to replicate the kind of swamp Amano shrimp came from in Japan.

My dad worked for U.S. Fish and Wildlife, So I get lots of input about what kind of soil is "proably" in swamps .... USGS reports confirm the things I was told in the U.S.

The sulfur loving bacteria also happens to be 'a' reason shrimp love swamps. They feed off bacteria and cyanobacteria.
My experiment started with five Amano shrimp in 2013, and they bred and I had 200 hundred of them within three months of introducing pyrite/sulfur cycle into the tank.

Ten months later I had a second wave of shrimp. But unfortunately, i did something ignorant. I switched from Chlorox Bleach to clean my tank tools with (because my mom's allergic to Chlorox/Chlorine), and tried OxyBleach a sodium peroxide bleach.
eg: Probably sodium hydroxide and carbonate in an adduct (interaction) with hydrogen peroxide. I don't mean a chemical "reacted" Na Peroxide; but I'm not totally sure on that.

Amano Shrimp are killed by even the smallest amount of peroxide. So the supposedly "cleaner"/safer environmentally more friendly bleach, actually killed them from just the tiniest residue. Regular chlorox didn't bother them (or honey bees) at all. Weird how our human ideas of "clean" chemicals and what "nature" needs can be two very different things. I'm pretty sure even 1 drop of 3% hydrogen peroxide could have euthanized all of the shrimp. Very depressing end to an excellent start....


Every chemical has it's place on the earth, and places that it should not be.
It takes intelligence to figure out what goes where, safely, not just television commercials about what's safe to use on your laundry and silverware and what isn't.





[Edited on 1-7-2020 by semiconductive]

Quote: Originally posted by semiconductive

But, no amount of reading can substitute for experience.

hmmmm..... yes and no.
Discussion:

In School, you have a mentor; or at least you've paid someone to be a mentor.
They have learned from their mentor... in a chain back to the first person who did an experiment.
Before that first experiment there was no "theory" that was "right."

In the saying, "which came first, the chicken or the egg?" There is a very clear, scientific, answer. It's the egg.
OOcyte, is a 'cell' ... and a chicken egg (for example) is nothing more than a large single cell that added a calcium wall.
A chicken is multiple cells put together.

The same applies to teaching and experiment. Teaching is the summation of many experiments over the centuries.
If your teacher is 'good', then most of what you learn will be 'correct' (but certainly not all of it, for you might misunderstand your teacher; or they might have misunderstood their own teacher.)

Don't misunderstand me; I'm not against pay-for-knowledge. What I'm against is 'paying for what doesn't help you solve your problem.' or prices which are too high to be practical.

This is partly in answer to another poster, so don't take the idea personally but in the general sense:
When the U.S. founded the Patent Office, the idea was to exchange *knowledge* of how to do things for the exclusive right of a few to exploit that knowledge for a few years; a competitive advantage. Eg: Don't waste your time solving what has already been solved is the point of the patent office.

But, if you or I can not replicate the experiments because the person depositing the knowledge with the patent office has purposely left out crucial details; then the idea of the patent office is being thwarted. If there is knowledge, it is lost or obcured beyond practical use and the country as a whole does not advance. Only a mentor, or teacher, with personal experience in the area (already) will be able to get anything out of a patent.

With that in mind, why then do people lie/hide information in the patent office? The most obvious reason is that power attracts corruption. Thomas Edison spent most of his life fighting lawsuits over the light-bulb for people who cheated and stole the knowledge he gave to the patent office *before* his patent right was used up ... in the end, I think the final analysis is the light bulb vs. lawsuit costs made it not very profitable to have patented the light bulb.

I have a patent. Over 13 us companies are producing it, and even using the language of my patent WORD FOR WORD. They have not paid the company that owns my patent one penny. THe states even threatened to sue the company that owns the patent if they tried to sue the companies making parts with my patent in them. The reason is they claim speculative inventors are really "thugs" attempting to blackmail companies IF they are not producing the patented item themselves.

Insurance fraud, and all kinds of things are interfering with the company being able to produce my patent directly; but they are about to do in the next 12 months. I have a bet with the owner of the company that they won't (in the end) profit from the patent directly in making profits. eg: Something for you to think about ....

The issue with the library is that you almost have to be able to solve your problem to be able to "look up" the resource necessary to "solve your problem." It's a "chicken and egg" problem, again....

Quote:

Quote: Quote: Originally posted by Ubya   not in science, you learn and thendo the experiment to be sure you understood. Not everyone does science that way; the method only requires a theory to test. I suppose montessori children could be taught the scientific method through guided accidents and explorations. But, in College, your explanation fits my memories of it. Lecture then lab ... and I nearly failed lab, but always passed lecture and tests. It's the only D I ever got in college, and I did graduate with honors well above a 3. like demonstrations, you learn a formula, and how they got it, so you know now hot to find it, you don't just learn the formula. in school you learn the theory, and then go to the lab to apply what you learnt, they may be standard experiments, you are not finding anything new, but it's a process, because if you learn something, run the experiment and it the results are not the same, you can understand what you did wrong in the experiment.

YES!!!!!!!! Exactly.
And even importantly, novelty of mistakes makes you remember them far better than if nothing ever goes wrong. The more ways you experience a subject, hearing, seeing, touching, doing, .... the better you will remember it.

sinensetin is not orange, i found one source that said it is white to beige https://m.chemicalbook.com/ChemicalProductProperty_EN_CB8237...

so i tried to find a UV Vis spectrum and check myself the absorbtion bands, no absorbtion in the visible part of the spectrum, aka it is colorless or white.

the page is wrong.

limonene is not orange though, i extracted myself an impure sample via steam distillation(is has other terpenes for sure)

I wish I had an Infrared spectroscopy system ... even a crude one. The Fourier transform allows you to at least infer what's likely to happen in the visible band from the bond energies detected in the IR. Commercial spectrometers are out of my league for price ... and building one is going to take a while. .

But: Quick color review, using digital camera.
Orange Oil, Howard, original Photo UN-retouched, uploaded.
Second shot taken with known changing variables, space-time of event, and intensity of lighting. Indoor vs. sun. Weight sampled twice just as a sanity check that no major loss of oil is occurring or major air changes to roughly air-tight bottle over time-change.

Picture1 -- original from opening post, but un-compressed full size with no digital editing or cropping. Sorry about bandwidth loss, internet users. ... but I just don't want any suspicion.

Picure 2- original weighing.
Picture 3- Picture of Orange Oil at a different space-time-coordinate.
Picutre 4. second weighing.

Several days have lapsed since I started this thread, the second space-time changed pictures were photoed today; I am limited in what I can "test" for to see what "varibales" may have changed.

Weight in original weighing 120.660mg.
Weight in second weighing 120.660mg.

No attempt to clean off changed fingerprints, or compensate for air pressure changes were made. It's weird to be within 1mg .... but sometimes I get lucky. Conclusion, no major loss (grams) of material has happened in the last several days. Conclusion is not proof, but merely a sanity check on madscience.

Color picker from original photo, in web-html format, exracted from howard using gimp, first weighing, and second howard. Format is web standard for color #RRGGBB.

Sample1 #f9c511, #fff616 ; second color shows sensor saturation, and will be discarded.
Sample2 #8c5d0f ; from first weighing picture
Sample3 #B38201, 914102 ; both samples good, will average.

Average color:
0xb2 RED normalize to 100%
0x79 GREEN 69%
0x08 BLUE 4%

Definition of web color orange in saturation of red (red=100%):

Color HTML / CSS
Color Name Hex Code
coral #FF7F50 rgb(255,127,80)
tomato #FF6347 rgb(255,99,71)
orangered #FF4500 rgb(255,69,0)
gold #FFD700 rgb(255,215,0) Green%=84
orange #FFA500 rgb(255,165,0) Green%=64
darkorange #FF8C00 rgb(255,140,0)

Conclusion, howard Orange oil (composite oil) is closest in color to Orange; but is on the spectrum between Orange and Gold colored. Gold is usually called "yellow" by little children using crayons.

SecondConclusion: None, no basis....


Hmmm....
Is the website, Wrong? I don't know, I didn't see a color listed. I did ask what makes Oranges "Orange", so go back and check the chat history if you want to know exactly who said what.

Thanks.

Quote: Originally posted by semiconductive

@ubya Missed this: Quote: limonene is not orange though, i extracted myself an impure sample via steam distillation(is has other terpenes for sure) Question: Extracted it from what? Oranges? What about the smell, does it "smell" orange like? I'm guessing no, but want to check. Also: How do you know that you have all possible isomerizations of Limonine that might affect color? Or liquids mixtures that might bring out a color. Dry copper sulfate, for example, is not the same color as hydrated copper sulfate. So, I was asking (originally) about whether color in oils is affected by some kind of ligand/complexing also. Do isomers always distill at the same temperature, or something? I'm missing some critical data on probability, here, and no specific data from chemistry books on Oranges. If chirality can affect polarization, then it seems likely to me that isomers could also affect other optical properties like color. So, the question all the answers in this thread have led me to is this one: Is there such a thing as pure limonene, for if there is rarely such thing as "hexane" but there's always "hexanes" (that smell). What's the definition of "pure" limonene, and how do you/I know? The Kerosine I use is odorless, "lamplighters" with ASTM markings that I *think* matching those in the government report I cited. It smells even less than petrolium jelly (vasaline); though even that could be considered an "odor", I suppose. I can't smell anything like gasoline from the kerosine, and I'd sure like to know how to test for hexane using fractional distillation and perhaps water. Same with limonene, I have a computer controlled mantle and distillation equipment. But with mixtures, it's hard to look up enough information to be able to separate what's in the liquid because of ... I forget the name, (azetrope?) when two liquids distill together preferentially over one; aka, the reason isopropyl alcohol is 99% and not 100% in typical stores.

Because the logical conclusion I came to of what you told me, based on what I know, is this:
There can be isomers of even simple chemicals that are not involved in chirality, so the possibilities I have to consider is broader than I imagined.

I do not know what properties those isomerizations could affect, color, bp, etc. I'm ignorant of many things, but not stupid. The difference is that I can be "cured" with proper information while stupidity is forever. lol.

You didn't, in the earlier post, say that entanomers were or were not the only factor that could cause changes to physical properties; or if you did, I missed it.
Draconic acid just mentioned that entantomers (which is a subset of isomerisations) do affect taste and smell.

I got an D (not an F) in Chemistry, the teacher's scathing comment was "Stop trying to do lab experiments like a graduate student. If the book doesn't say the reaction could be interfered with by an impurity, don't assume it will be in our labs. Do the same as the other students."

Ironically, I got nearly the same comment in my mechanical engineering survery course; (This is 25+ years ago, so I'm sure my memory of the quote isn't exact.) The teacher said, "The only reason you don't finish your tests and get an A instead of A+ is because you try to do the problems like a graduate student and solve the matricies with all entries; there are shortcuts you can take, that the other student's notice that speed up the process."

Let me reiterate, I came across a couple of data pages. The information I "saw" led me to believe I was "probably" ignorant of other factors.

eg: When I saw "D-limonene" I already knew limonene was not a single chemical, but a family of at least two isomers.
That's all I knew. ... but it was sufficient for me to be cautious.

Right and Left are chiralites. I studied amino acids in honors genetics class. But -- I didn't recall the exact meaning of the abbreviations from 25+ years ago. I didn't remember from the survey chapter on organic chemistry, which was ultra-simplified, that there were four designations for entantomers. I thought there were only two. So, when I saw two *different* abbreviations, I tentatively thought I had the complete set; and then was told, I was wrong -- and there are four designations.

So, since you're asking about my thought process:

D-limonene is "one" isomer. Isomer is a general word that I know the meaning of from Greek. It is a real Greek word, and so is aromatikos. Azetrope, is not. I have never read that word in Greek literature, and it looks like a novice in Greek made it up. In plants, and Greek, Trophism is a turning toward -- as in turning toward light, or turning toward gravity; a "place". So, azetoph does contain the idea of twisting and changing direction in most uses. Eu-Trophic is "Good in every direction" (Fertilized water with algae growing everywhere, uniformly, is eutrophic.) But when I read a-ze-trope; I literally read, no-boil-twisting toward. It's not a good mnemonic (to me) for liquids refusing to separate under boiling ... but at least it has the idea of boiling.

My point is that everyone learns by memory devices about words. My path is different from yours.

However, if there is one isomer, then there can be others (plural). I don't have your level of knowledge on "probability" or "lliklihood" of what causes bonds, etc. or what these other BROAD possibilities of chemical morphologies entail. As an Electrical engineer, I only took one full year of chemistry 100 and 200 level. And they didn't even think it was worth teaching us that "hydrogen" becomes hydronium ions in aqueous solutions. I thought the hydrogen just wandered around in the solution with a positive charge and "didn't" react with other chemicals at all or totally reacted (all or nothing) ... sort of like I'm told "smells" do with the nose. It's hard for me to "guess" the full meaning of statements I was told by teachers 25 years ago, or people in these threads; I don't mean to act like I'm ignoring your instruction; I'm just trying to be conservative and not jump to unwarranted conclusions. I do know that isomer is correct, even if it contains ideas that don't apply to my particular problem;

I do NOT know if there are variations of the idea Isomer, which could apply to the problem; ones I'm not aware of, and you're perhaps assuming don't apply when they do. You are debugging my use of language, and I think that's laudible. It's not just simple ignorance. In such an ambigous case, using the broad term is conservatively correct in covering the logic of the situation until an explanation is given as to why it doesn't apply.

I'll give another example. I was taught what "emprical formula" means. I was taught what molecule means. So, when the teacher talked about ONE hydrogen atom, and ONE chlorine molecule reacting to make a "molecule." I understood that.

But: I learned, rather harshly, that if there is more than one hydrogen and one chlorine atom involved in a crystal; the idea of "molecule" no longer applies. I had no way, from what I was taught 25 years ago, to figure that language change out. Draconic acid, I think it was, was the person who brought to my attention my ignorance rather sharply a few years ago on this site. But "molecule" is one of the basic ideas taught in chemistry, which I am now being told I had wrong. I was not given a generic word to represent the smallest unit of a chemical that still has the chemical's property and would be correct to use in both the situation where it's crystalline ... vs. gas, or other state. Chemistry is a VERY steep learning curve. It seems to have more "exception" than it does, rules. I am a rule based person, and chemistry will always be difficult to me.

FYI:
The judges in my country are apt to take any ignorance, however small, as grounds to say I'm a hazard to my daughter and never let me see her again. Notice why Cody, in this video, says he is NOT going to do this experiment as it is NORMALLY done in industry.

His comment is from 8 to 9 minutes.
https://www.youtube.com/watch?v=qkyPvhapxQs

"ATF" is a U.S. law enforcement agency that arrests people who make bombs, guns, or other lethal items without a permit.
They also are involved in arresting people for "drugs"; "Alcohol, Tobacco, and Firearms" is what A.T.F. stands for.

In my country, there is a rulership/governance based on ignorance and fear in many small towns. Judges are driven by public opinion, which is OFTEN very ignorant, to find excuses for denying people their rights if they are 1) male 2) involved in chemicals that might be drugs 3) mentally ill (including things, like being obsessive compulsive and washing your hands too often, or being afraid of chemicals that TV commercials say are safe. ) This is especially true in the current political environment because the "mee too" sexually assaulted women make judges more likely to condemn a man as a sexual predator or drug addict, because there are spectacular cases in our country's history. Innocent until proven guilty is a nice theory in my country, but it often is a fantasy.

I'm glad that the orange colored pulp in that pictures you showed were Orange Rhinds. I didn't know for sure, as you didn't say. The last distillation I saw had curly cuts of peel that were still recognizable, so my eyes didn't register what I was looking at when I saw your pulp. Which is why I asked the follow up question.

If you think I write too much ... well, you're not the only one. Here's a chineese making a comment about me, and he has a language barrier to English:

However, I have found talking with this person EASIER than talking with people who assume I have telepathy about what they mean, or how they learned vocabulary for chemistry. Something to think about if you are trying to teach to a general audience, and you have "trolls" on your site....

I'm not sure whether to take this as a compliment, or insult, but it's at least an honest remark.

Exactly!

But here's another issue with generalizations and "rules of thumb" @draconicacid ; Although polarization is not directly related to "color of light", optically active fluids that affect polarization *can* affect light color. I appreciate your reasonable thought; but I have to sort what people tell me for relevance to a particular problem and look for "exceptions."

Look on the Wikipedia page for Iron Pyrite. Notice what happens to the color when they take a picture of it through a polarized lens. https://en.wikipedia.org/wiki/Pyrite

Iron Pyrite is also one of the reasons H2SO4 in the original photo is Orange-ish.

Note: The small washer I took a picture of, looks barely orange. If I tilt it at a roughly a 30 degree angle, it turns a brilliant blue. That's what my eye sees with no polarizer involved. With my camera lens ... I can't capture the effect. (DANG!)

But for the same reason, the liquid I'm studying, *seems* likely to be optically affected by polarization twists of chemicals (D-limonene) in contact with dissolved pyrite.

So, even though I appreciate your comment ... I don't ascribe to it the kind of certainty that is a "rule." I don't know how often chemicals have polarization sensitive properties (? Di-Chromism ?)

I'm not a highly theoretical person ... I really do like to test what people tell me; but I can't even figure out if I should call the smallest amount of chemical known as cymene -- a molecule. It has bonds which actually resonate and aren't fixed as in the wikipedia page. So, I have no idea what effects cymene would have on another cymene 'molecule' when next to each other. Do they resonate and make "micro" or "picosecond" bonds that break again? I'd like to know what to call the smallest amount of a chemical, so that I can talk about the "nominal" electronic configuration, and not confuse people if it's in a crystal (solid or liquid) or not.

On-to-distillation:

Hmmm ... I think a simple distillation, a so called "short" distillation is typically just a boiler, a short tube bent at an angle and a room temperature collection flask.

Next (more complicated) is a longer vertical column (uncooled), then (more complicated) a Vigeruex tube, or Allihin condenser for doing reflux; followed by a angled tap and a cooled condenser.

And it can even get more complex from there!!!!

I love this ....
See about 3 minutes 30 seconds into this video. (3:30) Wow !
https://www.youtube.com/watch?v=BUJ2q5-K3zs


One of the big issues I've been fighting is the turbulence of boiling.
For example, since I'm concentrating H2SO4, this following example video shows some of the same things I ran into. It's also why I have vacuum taps, and taken other precautions. ( I didn't have any disasters like Doug did... )

See about 6:30-7:00 in the video. And especially the advice in 11:35-13:00
https://www.youtube.com/watch?v=wMOrK7cysqY

When water drips back into a boiling solution, it almost invariably is weaker concentration than the solution itself and has a lower boiling point; and this problem isn't limited to H2SO4 and water vapor. The result is splashing of tiny droplets high up into a reflux column and extremely rapid re-boiling. In extreme cases, my 50 mL boiling flasks have cracked because the temperature difference between the refluxing liquid and the heated liquid is so great that over 100C difference exists on the flask walls above the fluid and it goes from "dry" to "wet" with a drip. This problem becomes even more pronounced when distilling small amounts of liquid.

This is another reason I bought a computer controlled heating mantle ... I don't want the temperature to "run away" when the fluid level gets very low in the boiler. ( It's hard to clean burnt ***** out of flasks. )

From my perspective (and this obviously varies with experience):

I think the two main enemies causing fluid loss and bad separation in distillations, appear to be turbulence and rapid phase changes. Boiling splatters a fair amount of liquid onto "higher" locations than would happen if the fluid was vaporizing slowly. Lamellar flow is much more controllable than boiling and has errors over smaller "heights."

Doug's video also shows why I carefully lap my glass joints to make air-tight, fluid tight seals possible. But not TOO polished, or the glass will weld together and permanently stick. I'm considering adding teflon dust to the top of my 24-40 joints, near the outside ... and heating it to 275-350C in order to sinter the teflon. Eg: to prevent the glass from "welding"....

If you look at my pictures, you can see that the kerosine is over the top of a 24-40 joint .. but .. there is no leakage. ( I also have vacuum taps, so as not to have Doug's problems. ) People can't reproduce what I've done without a little bit of lapping work, or slightly different equipment.
But what I'm doing is not just "theory."

When doing quick distillations of small amounts, I've found that the thermal mass of a column also causes major losses; eg: since it never "gets up to temperature" to 're-boil' liquid in the column. So, quite a bit of product just falls back down into the boiling flask, or else stays as droplets on the reflux column and is often lost or destroyed (oxygen,etc). There's also a tiny bit of loss as "wetting" the column in a film. In these cases, it can take hours for a very thin film to "drip" back out of a column. ( Surface tension?, I wonder if surfactants might help... )

So, what I'm really more interested in is ways to do slower distillation without quite boiling, and temperature controlling the reflux column to minimize adhesion and condensation due to under-heat of the glass.

The point is -- with quick flow, the gas mixes in the reflux tube and doesn't have much time to separate before re-condensing. I think either the slower the flow, or the more surface area, the more effective theoretical "plates" a distillation column will have. Slower distillation should yield more product and less losses, in a shorter column. ( I am testing the idea.)

The down side to slow flow, is the reflux column can cool too quickly for the vapor to ever make it to the "top" and a lot of product you would be happy with drips back into the boiler over and over again. This makes the distillation (or slow evaporation) indefinitely long. But it DOES allow me to work with small amounts of solution (eg: 10mL), and get a large amount of product percentage wise, say 9.5mL out.

I remember from thermodynamics class about the efficiency of condensers using counter-flow of coolant. So, one way to make slow distillation precision ... is to simply insulate the reflux column. A fishtank pump can be hooked to a computer and a thermometer placed at the top of the allihn condensor to regulate the temperature of reflux. So it doesn't depend on how much liquid you are distilling, but on fixed and precision controlled temperatures. Air will flow when the temperature gets too hot cooling the refluxer... and stop if it's too low. This process can be made multi-stage, for better control of heat. I only have three condensors, a Vigereux, a Allihn, and a straight pipe with water jacket. But I could easily build a two stage refluxer with the straight pipe and Alihn, each temperature controlled separately. Fish tank pumps are only around $20... so its cheap. As a final addition, I might consider actively heated boiler joint, so almost no liquid drips back into the boiler. It will separate purely as a thin film and vapor in the tubes.


[Edited on 7-7-2020 by semiconductive]

Here's the latest on the electroplating. Unfortunately, the solution broke down over several days releasing hydrogen and who knows what else.
The fluid level dropped enough that the washer came out of solution between weighings, so I can't make any conclusions of the efficiency (electrons moved/grams iron or iron sulfide plated); So, I don't know how much acid I'm creating and re-etching the iron, vs. how much disappeared as gas (electrolysis), vs. whats on the washer.
I'll have to re-do the experiment.

But these photos show the typical color of a typical iron plate with insufficient sulfide to make it gold color. In general, Iron plates a light gray when no sulfide is present, and anywhere from black (very magnetic) to golden (non-magnetic). Black plating occurs with oxygen or sulfide. The iron is very reactive to oxidizers in solution.