| Pages:
1
..
25
26
27
28
29
..
103 |
Texium
Administrator
Posts: 4516
Registered: 11-1-2014
Location: Salt Lake City
Member Is Offline
Mood: PhD candidate!
|
|
One thing I've always wondered about, what causes HCl to turn bright yellow when it reacts with concrete? I always refill my small bottle over
concrete, and if I spill any it always bubbles up and turns bright yellow.
|
|
|
DraconicAcid
International Hazard
Posts: 4278
Registered: 1-2-2013
Location: The tiniest college campus ever....
Member Is Offline
Mood: Semi-victorious.
|
|
Iron impurities, probably.
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.
|
|
|
learningChem
Hazard to Others
Posts: 182
Registered: 21-7-2011
Member Is Offline
Mood: No Mood
|
|
Thanks Cheddite Cheese!
|
|
|
Brain&Force
Hazard to Lanthanides
Posts: 1302
Registered: 13-11-2013
Location: UW-Madison
Member Is Offline
Mood: Incommensurately modulated
|
|
What is an ideal container for storing lithium metal? I have some xylene and one of those 8 oz flasks that you can find at a Wal-Mart, but I fear
it'll be too difficult to remove the lithium, as the neck is narrow.
Also, would it be a good idea to add a few drops of methanol to clean the metal surface, or is it too reactive for this?
[Edited on 8.9.2014 by Brain&Force]
At the end of the day, simulating atoms doesn't beat working with the real things...
|
|
|
AlphaDecay
Hazard to Self
Posts: 60
Registered: 20-3-2014
Location: Uranium-238
Member Is Offline
Mood: Emitting Helium-4
|
|
I've already asked this before but I really wanna make sure of it. Does mixing ammonium sulfate and potassium nitrate really make ammonium nitrate?
Has anyone really tried this reaction? I dont want to any waste chemicals.
Here is my post: http://www.sciencemadness.org/talk/viewthread.php?tid=29592#...
Sorry if I'm asking this again, but I really want to be sure of it.
|
|
|
Metacelsus
International Hazard
Posts: 2531
Registered: 26-12-2012
Location: Boston, MA
Member Is Offline
Mood: Double, double, toil and trouble
|
|
Yes, but the ammonium nitrate will still have some potassium and sulfate in it.
|
|
|
Oscilllator
National Hazard
Posts: 659
Registered: 8-10-2012
Location: The aqueous layer
Member Is Offline
Mood: No Mood
|
|
If you mix them in a solution you wont have either of those things, you will have a mixture of ammonium, potassium, sulfate and nitrate ions in water.
If you want to see which one will crystallise out first, I suggest you check the rather comprehensive list on wikipedia, it's quite useful.
|
|
|
Metacelsus
International Hazard
Posts: 2531
Registered: 26-12-2012
Location: Boston, MA
Member Is Offline
Mood: Double, double, toil and trouble
|
|
Potassium sulfate will crystallize first, but it is still pretty soluble, so you won't get all of it out.
|
|
|
AlphaDecay
Hazard to Self
Posts: 60
Registered: 20-3-2014
Location: Uranium-238
Member Is Offline
Mood: Emitting Helium-4
|
|
Ok, thanks. Another question, sorry if it will sound stupid, but, it is better to ask first than regreting after making a mistake. Consider a stand
with clamps attached to it. If I'm going to hold an erlenmeyer in the clamp, for example, can I break it by forcing the clamp too much? Or this harldy
happens? I am confused, if I don't force it enough, it will fall, if I force too much, will it break? Imagine if it falls during an chemical
reaction...
|
|
|
bismuthate
National Hazard
Posts: 803
Registered: 28-9-2013
Location: the island of stability
Member Is Offline
Mood: self reacting
|
|
Well I doubt it will fall because of the lip on the flask so i don't put it on too tightly. Also what does SWIM mean? I keep on seeing it here.
|
|
|
elementcollector1
International Hazard
Posts: 2684
Registered: 28-12-2011
Location: The Known Universe
Member Is Offline
Mood: Molten
|
|
SWIM means "someone who isn't me", and is common slang (and a massive red flag) for drug dealers.
Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
|
|
|
Crowfjord
Hazard to Others
Posts: 390
Registered: 20-1-2013
Location: Pacific Northwest
Member Is Offline
Mood: Ever so slowly crystallizing...
|
|
My advice would be to clamp tight enough to hold, but without forcing. I've stripped the threads on the screw to one of my good three-fingered clamps
this way.
SWIM means "someone who isn't me," and is a long-since abandoned way of avoiding self-incrimination. I think it got started at the Hive? Anyway, it
has no place here, but wannabe drug cooks and kewls and whatnot still seem to like to use it.
Whoops, haha, beat to it.
[Edited on 10-9-2014 by Crowfjord]
|
|
|
AlphaDecay
Hazard to Self
Posts: 60
Registered: 20-3-2014
Location: Uranium-238
Member Is Offline
Mood: Emitting Helium-4
|
|
Sorry the ignorance but, is this "strip the threads on the screw" an expression?
What does it mean?
|
|
|
Crowfjord
Hazard to Others
Posts: 390
Registered: 20-1-2013
Location: Pacific Northwest
Member Is Offline
Mood: Ever so slowly crystallizing...
|
|
Nope, it was meant to be taken literally. The threads are the helical (spiral) part that make a screw what it is. To strip them means to remove or
break them off, smoothing the shaft of the screw, thereby making it non-functional as a screw.
|
|
|
AlphaDecay
Hazard to Self
Posts: 60
Registered: 20-3-2014
Location: Uranium-238
Member Is Offline
Mood: Emitting Helium-4
|
|
Oh, I see... Also I bought a 1L distillation flask, is it suitable to distill nitric acid from H2SO4 and KNO3? Or it needs to be a complete aparatus?
[Edited on 10-9-2014 by AlphaDecay]
|
|
|
Crowfjord
Hazard to Others
Posts: 390
Registered: 20-1-2013
Location: Pacific Northwest
Member Is Offline
Mood: Ever so slowly crystallizing...
|
|
Assuming the flask is really just a flask (not a retort or something similar) then a complete apparatus will be needed. This includes a distillation
head, condenser (either a Liebig or West type will do), a take-off adapter (optional, I suppose), and of course some sort of vessel with which to
collect distillate.
|
|
|
AlphaDecay
Hazard to Self
Posts: 60
Registered: 20-3-2014
Location: Uranium-238
Member Is Offline
Mood: Emitting Helium-4
|
|
Damnit, it is one like this http://m.ebay.com/itm/170984880403?nav=SEARCH ...
|
|
|
Crowfjord
Hazard to Others
Posts: 390
Registered: 20-1-2013
Location: Pacific Northwest
Member Is Offline
Mood: Ever so slowly crystallizing...
|
|
Hmm, yeah to use that you will need a non reactive stopper of some sort to plug the top with, and probably a condenser. It depends on how long the
side arm is, but if it is as small as the one in that photo, a separate condenser would probably be the safest and most effective way to go.
|
|
|
AlphaDecay
Hazard to Self
Posts: 60
Registered: 20-3-2014
Location: Uranium-238
Member Is Offline
Mood: Emitting Helium-4
|
|
In fact the flask is about to arrive. So when it arrives I will post here the lenght of the side arm, then you tell me if its ok to distill without a
condenser.
|
|
|
Texium
Administrator
Posts: 4516
Registered: 11-1-2014
Location: Salt Lake City
Member Is Offline
Mood: PhD candidate!
|
|
Yeah, you'll definitely need a condenser, but you won't need the distillation head since your flask already has the side arm.
Basically, something like in this picture:
|
|
|
AlphaDecay
Hazard to Self
Posts: 60
Registered: 20-3-2014
Location: Uranium-238
Member Is Offline
Mood: Emitting Helium-4
|
|
That makes things much easier, just need to get some money to buy a condenser 
...
[Edited on 10-9-2014 by AlphaDecay]
|
|
|
alexleyenda
Hazard to Others
Posts: 277
Registered: 17-12-2013
Location: Québec, Canada
Member Is Offline
Mood: Busy studying chemistry at the University
|
|
Quote: Originally posted by Brain&Force  | What is an ideal container for storing lithium metal? I have some xylene and one of those 8 oz flasks that you can find at a Wal-Mart, but I fear
it'll be too difficult to remove the lithium, as the neck is narrow.
Also, would it be a good idea to add a few drops of methanol to clean the metal surface, or is it too reactive for this?
[Edited on 8.9.2014 by Brain&Force] |
I used to store my lithium in a mason jar (cheap, airtight, wide neck) and use a relatively rigid wire twisted in the shape of a disk with one end
coming out of the oil (to lift it without a mess) to keep the lithium pushed under the oil.
Help us build the Sciencemadness Wiki! Every question and tips about amateur chemistry two clicks away, wouldn't that be awesome?!
sciencemadness.org/smwiki
|
|
|
Texium
Administrator
Posts: 4516
Registered: 11-1-2014
Location: Salt Lake City
Member Is Offline
Mood: PhD candidate!
|
|
I heated some copper(II) carbonate to make some copper(II) oxide for use in a later experiment, and it turned out unusually brown... Normally I'm used
to seeing CuO be solid black, but this particular stuff is very dark brown, like coffee grounds.
Any ideas about what is causing this?
If it helps, I used copper carbonate that I made a long time ago that was cleaned very thoroughly, and I heated it strongly with my Bunsen burner
while stirring it until it had all changed color.
Edit: I had 2.00g of CuCO3 to start with, and now I have 1.70g of CuO, which would be about .005mol of CuO more than there is supposed to
be (theoretical yield of CuO should be 1.29g), so I'm thinking that the discoloration is caused by carbonate that didn't decompose. That surprises me,
because the first batch of copper carbonate that I made would go black from the heat of a space heater, while this batch can seemingly survive a few
minutes of roasting from a Bunsen burner...
Later I'll put it back in a crucible and heat it more, and see if it will look more black and weigh the amount that it's supposed to.
[Edited on 9-13-2014 by zts16]
|
|
|
bbartlog
International Hazard
Posts: 1139
Registered: 27-8-2009
Location: Unmoored in time
Member Is Offline
Mood: No Mood
|
|
Any possibility that some of your copper is still copper(I)? A bit of red Cu2O might give you a brown oxide rather than a solid black
one...
The less you bet, the more you lose when you win.
|
|
|
Texium
Administrator
Posts: 4516
Registered: 11-1-2014
Location: Salt Lake City
Member Is Offline
Mood: PhD candidate!
|
|
| Quote: Originally posted by bbartlog | | Any possibility that some of your copper is still copper(I)? A bit of red Cu2O might give you a brown oxide rather than a solid black
one... |
I highly doubt it, as it would have had to have been reduced from copper(II) since I started with
CuCO3, and that would have made it weigh less than it was supposed to since it would contain less oxygen.
|
|
|
| Pages:
1
..
25
26
27
28
29
..
103 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
