| Pages:
1
..
48
49
50
51
52
..
104 |
Detonationology
Hazard to Others
Posts: 362
Registered: 5-5-2015
Location: Deep South
Member Is Offline
Mood: Electrophillic
|
|
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.
“There are no differences but differences of degree between different degrees of difference and no difference.” ― William James
|
|
|
Texium
|
Threads Merged
16-1-2016 at 08:44 |
hissingnoise
International Hazard
Posts: 3940
Registered: 26-12-2002
Member Is Offline
Mood: Pulverulescent!
|
|
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
International Hazard
Posts: 4332
Registered: 1-2-2013
Location: The tiniest college campus ever....
Member Is Offline
Mood: Semi-victorious.
|
|
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.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
|
|
|
The Volatile Chemist
International Hazard
Posts: 1981
Registered: 22-3-2014
Location: 'Stil' in the lab...
Member Is Offline
Mood: Copious
|
|
...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.
|
|
|
RogueRose
International Hazard
Posts: 1592
Registered: 16-6-2014
Member Is Offline
|
|
What kind of cotton comes in the top of medicine/pill bottles?
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
International Hazard
Posts: 2961
Registered: 18-1-2007
Location: UTM
Member Is Offline
Mood: LaGrangian
|
|
usually cellulose i.e. cotton from agricultural sources.
"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
|
|
|
Texium
|
Threads Merged
21-1-2016 at 16:52 |
DubaiAmateurRocketry
National Hazard
Posts: 841
Registered: 10-5-2013
Location: LA, CA, USA
Member Is Offline
Mood: In research
|
|
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
International Hazard
Posts: 1694
Registered: 28-12-2010
Member Is Offline
Mood: No Mood
|
|
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??
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? |
"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
Administrator
Posts: 6320
Registered: 4-10-2014
Location: At home
Member Is Offline
Mood: Most of the ducks are in a row
|
|
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
Hazard to Others
Posts: 103
Registered: 25-2-2012
Location: Australia
Member Is Offline
Mood: Thinking!
|
|
@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.
Li
|
|
|
j_sum1
Administrator
Posts: 6320
Registered: 4-10-2014
Location: At home
Member Is Offline
Mood: Most of the ducks are in a row
|
|
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
Hazard to Others
Posts: 381
Registered: 19-8-2015
Location: New York
Member Is Offline
Mood: Taking it easy
|
|
Alright, how can I compress powdered charcoal into rods?
Check out the ScienceMadness Wiki: http://www.sciencemadness.org/smwiki/index.php/Main_Page
"All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident."
—Arthur Schopenhauer
"¡Vivá Cristo Rey!"
—Saint José Sánchez del Río |
|
|
RogueRose
International Hazard
Posts: 1592
Registered: 16-6-2014
Member Is Offline
|
|
MgOH from MgSO4 + Ammonia - different results than expected
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?
|
|
|
Texium
|
Threads Merged
27-1-2016 at 13:54 |
The Volatile Chemist
International Hazard
Posts: 1981
Registered: 22-3-2014
Location: 'Stil' in the lab...
Member Is Offline
Mood: Copious
|
|
You could always dissect a 6v battery to get four carbon rods. I don't think making them is very feasible, though.
|
|
|
Velzee
Hazard to Others
Posts: 381
Registered: 19-8-2015
Location: New York
Member Is Offline
Mood: Taking it easy
|
|
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]
Check out the ScienceMadness Wiki: http://www.sciencemadness.org/smwiki/index.php/Main_Page
"All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident."
—Arthur Schopenhauer
"¡Vivá Cristo Rey!"
—Saint José Sánchez del Río |
|
|
elementcollector1
International Hazard
Posts: 2684
Registered: 28-12-2011
Location: The Known Universe
Member Is Offline
Mood: Molten
|
|
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?
Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
|
|
|
ganger631
Hazard to Self
Posts: 53
Registered: 15-8-2014
Member Is Offline
Mood: Plata o plomo
|
|
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
Hazard to Others
Posts: 381
Registered: 19-8-2015
Location: New York
Member Is Offline
Mood: Taking it easy
|
|
| 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]
Check out the ScienceMadness Wiki: http://www.sciencemadness.org/smwiki/index.php/Main_Page
"All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident."
—Arthur Schopenhauer
"¡Vivá Cristo Rey!"
—Saint José Sánchez del Río |
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by Velzee | | 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.
|
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
Hazard to Others
Posts: 381
Registered: 19-8-2015
Location: New York
Member Is Offline
Mood: Taking it easy
|
|
| Quote: Originally posted by blogfast25 | | Quote: Originally posted by Velzee | | 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.
|
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] |
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.
Check out the ScienceMadness Wiki: http://www.sciencemadness.org/smwiki/index.php/Main_Page
"All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident."
—Arthur Schopenhauer
"¡Vivá Cristo Rey!"
—Saint José Sánchez del Río |
|
|
lysander
Hazard to Self
Posts: 69
Registered: 12-7-2015
Member Is Offline
Mood: No Mood
|
|
Sodium ferrocyanide (yellow prussiate of soda)
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
Administrator
Posts: 4580
Registered: 11-1-2014
Location: Salt Lake City
Member Is Offline
Mood: PhD candidate!
|
|
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)
|
|
|
Texium
|
Threads Merged
31-1-2016 at 08:51 |
UC235
National Hazard
Posts: 565
Registered: 28-12-2014
Member Is Offline
Mood: No Mood
|
|
http://www.elementalscientific.net/store/scripts/prodView.as...
|
|
|
lysander
Hazard to Self
Posts: 69
Registered: 12-7-2015
Member Is Offline
Mood: No Mood
|
|
Sodium ferrocyanide
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
International Hazard
Posts: 2684
Registered: 28-12-2011
Location: The Known Universe
Member Is Offline
Mood: Molten
|
|
| Quote: Originally posted by Velzee |
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. |
Sounds exactly like the anthracite I worked with - that stuff needs air influx and strong ignition (kerosene, etc.) to even light.
Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
|
|
|
| Pages:
1
..
48
49
50
51
52
..
104 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
