jdurg

I was just wondering what the worst chemical accidents people here have experienced, and what chemicals they are particularly sensitive to. Here are mine. 1): In a high school chem lab I needed to make a sodium silicate solution, but decided to do it outside of a fume hood. As I was weighing out the powder, a fine breeze moved by the area I was working in causing the powder to puff out into the air. I inhaled a pretty big breathful of it and started coughing uncontrollably. They had to pull me out of the lab and into the hallway until I could stop coughing. It was horrible. I had to visit a doctor later that day to get my lungs checked out. Thankfully, there was no permanent damage. Just a big scare. 2): Another time in high school we were bending glass tubing, and the tube I was bending was previously used to carry bromine vapor. As I heated the tube, bromine leached out of the glass and into the air. I, sadly, was standing in between where the vapor was coming from and the air vent overhead. I got a pretty big whiff of bromine and was quite ill for a good hour or so. 3): In high school, a stupid lab partner decided that he wanted to chuck a huge piece of sodium into a beaker of water. I didn't have gloves on at the time, but knew that if the sodium hit the water, a major incident would occur. I moved my hand above the beaker and caught the sodium bare-handed and wound up with a minor chemical burn on my palm. 4): College analytical lab: We were working with some concentrated nitric and sulfuric acids for various experiments, and I forgot to label my beaker of H2SO4. When it was time to clean up I thought the beaker was water and picked it up haphazardly and put my thumb in the liquid. That REALLY hurt as my thumnail dissolved and my thumb burnt. As I was moving towards the sink with the beaker in my hand, my forearm grazed the top of an open nitric acid bottle. So on my forearm I received a vicious HNO3 burn which left my skin yellow for a good two weeks. 5): College organic lab: I spilt diethyl ether on my jacket and let it evaporate during lab. After lab I went outside and lit a cigarette, but some ether vapor was still present. A bright flash went off and my eyebrows were gone. lol. 6): Freshman year of college: I was doing the inventory of our vast chemical supply and had to spend a few hours in front of the cyanides and various other cyanide containing compounds. For hours I was sitting there writing down what we had and inhaling the faint odor of bitter almonds. For the next two weeks, I was dead tired and barely able to wake up in the morning. Apparently I had a sub-lethal case of cyanide poisoning. I still can't believe how exhausted that made me. 7): Sophomore year of high school: In my biology lab we were dissecting giant clams. My teacher was old fogey who was still using formaldehyde to preserve specimens instead of formalin. As my lab partner and I were dissecting the clam, he accidentally pressed on the stomach causing a jet of formaldehyde to spray onto my goggles and onto my face. My skin immediately began to slough off leaving me red and raw for a good few days. Thank god I was wearing goggles. I think I have more stories, but since I'm at work right now I really can't think of any more. I'll add to this as I come up with them. For chemical sensitivities, I am very sensitive to ethyl acetate. The slightest odor of it gives me vicious headaches. That's probably from all the esters that I worked with during my internship at a forensic chemistry lab. (GC/MS stuff). My nose is very sensitive to smells, and I can detect odors in astonishingly low concentrations. I guess that's a good thing because I can smell halogens, thioesters, sulfur gasses, nitrogen oxides, ozones, cyanides, and virtually any compound far before anyone else can and before they become toxic. This came in handy once during a toxicology lab when an arsenous oxide source was accidentally put outside of a fume hood. I was able to smell the VERY faint garlic odor far sooner than anybody else and we were able to hurridly put the beaker back in the hood before it became really dangerous. Wow. I've had a lot of "incidents" in my life.

Organic chemistry can be the most painful chemistry course you ever take, or it can be a piece of cake. The VERY important thing to remember is that before moving on to another topic, make sure you fully understand everything you've been taught. O-Chem builds upon things you've learned in the past, so it's very important that you master what you're currently learning before moving on to more complex topics. Physical Chemistry is the same way. (Physical Chemistry, however, can be hell even if you know what you're doing).

Sodium nitrite is also used as a preservative when making sausages.

Yes it does. When lightning occurs, nitrogen and oxygen are fused together forming nitrogen oxides, and oxygen forms ozone with itself. This leads to that funky smell you notice when there's a thunderstorm in the area, or when you're near a bunch of electrical equipment.

I was going through my back closet and saw that I had an old amber glass bottle that I had kept Iodine in for a while. To clean the bottle, I had filled it with isopropanol a few years ago and forgot about it. Now I have a superconcentrated iodine solution. I decided to just soak a penny in that for a while until enough corrosion has occured to remove the outer copper covering. Some zinc will wind up being destroyed, but not too much as long as I watch it every day and occasionally clean the penny. (Though all this dissolved iodine will make a mess. heh.)

He's wondering if when lightning strikes water, does the electricity split any of the water into hydrogen and oxygen molecules?

Whether it was cis or trans would depend on the two constituents you were isolating. If you were talking about the Cl and I, it would be described one way, and if you were talking about Cl and Br, it would be described another. I think.

I've done that before. We did it in High School Chemistry lab. It was pretty neat. We also took a copper penny and soaked it in a strong NaOH/powdered Zinc solution, then heated the penny in a bunsen burner flame. The copper and zinc alloyed and made the surface a nice golden brass color.

hehe. The idea is fine, but me + high levels of heat generally = UH-OH. lol. I do have a few zinc samples from where I used a grinder and ground away the copper outer plating. But having a sample that looks just like a penny, but made of zinc, would be pretty cool to have.

Well, if the two constituents are the same, then there would be no cis or trans definition since they'd be exactly the same. In order for cis or trans to apply, the two constituents MUST be different. For example, with H2C=CH2, all constituents are the same so there is no cis or trans designation. But if you have two different constituents, like FHC=CHBr, then you could have a cis-trans designation. The cis and trans designations define different constituents. The H atoms don't really apply. In the example I gave, it's the Br and F that define cis or trans.

Well, the reason why I want the zinc un-harmed is that I'd like to have the impression of the penny, but without the copper. I think it'd be pretty neat to show that a penny is made out of pure zinc, and removing just the copper part would show the original penny, but made out of zinc. I'll have to get some NH4NO3 and try the copper removing that way. One question though; since I'd have no use for the solution afterwards, how would I go about making it not 'KA-BOOMABLE'?

The attachments to the adjascent carbon atoms do not have to be the same. You can have a cis, or trans, isomer with a Br on one side and a methyl on another.

I have a quick question. I would like to remove the copper coating from a modern U.S. Penny in order to obtain the zinc inside, but with the form of a penny. Is there any easy, relatively safe, way to remove the copper without damaging the zinc? I was thinking of electro-plating the copper off of it, but I figured that the zinc would react with the copper and displace it from solution. Is there a simple chemical way? Could I just soak the penny in bleach, and every day or so take it out and remove the copper chloride/hypochlorite that builds up on the surface until all the copper is gone? I'm just having some cerebral flatulence with this one.

And with the alkali metals, the metal oxide is soluble in water and isn't strongly bound to the metal. Therefore, it will expose more of the metal to reaction. While aluminum is pretty darned reactive, the oxide is NOT soluble in water and it adheres to the metal very strongly, thus protecting it from further reaction.

Are you sure about HF being ionically bonded? I always thought that a compound that exists as a liquid or gas at room temperature was covalently bonded. I know that HCl is covalently bound, but easily ionizes in a water solution. Okay. I did some further research and HF is definitely NOT ionic. It is a polar covalent bond, but assuredly not ionic. For a bond to be ionic, it generally must have an electronegativity difference of 2.0 or greater between the atoms. The difference between H and F is only 1.9 so it a strongly polar covalent bond.

I think that Beryllium exists as a polyatomic molecule. Mercury behaves that way as well, I believe.

An element can be without a subscript. For example, H2O is an empirical formula. An empirical formula just means that the elements in the molecule are represented in their lowest whole number ratios. So the chemical formula for hydrogen peroxide is H2O2, but the empirical formula is HO.

When you're thinking about the partial charge on water, what would you think has a stronger charge: an ion or a water molecule? The complete charge on the anions and cations provide a much stronger attraction for the water molecule as opposed to the weaker partial charge on the H2O molecules. Now, you might be thinking "How can there be a charge on the salt if it hasn't dissolved yet?" Well, the way a salt is composed is alternating positive and negative ions. At the edges, these ions are exposed to the water which has a slight charge on certain parts of it. What will happen is that the particles at the edges of the salt will see the water and want to move closer to the water molecules which can surround it in a more thermodynamically stable manner than the other ions can. Once one of them has moved away, it exposes more and more. Eventually the salt has totally dissolved. When the ion is fully solvated, it is not neutral. It still has a charge because it never has any electrons added to it or removed from it. They are still either positively charged or negatively charged, but they're stable due to the water molecules around it. Also, remember that electricity is not just the presence of electrons. Electricity is the movement of electrons from a negatively charged source to a positively charged source. A salt dissolved in water can carry electricity because the electrons will move from the negative source through the water via the ions, and to the positive side. (Damn. It sounded so clear in my head, but I can't get it out in words.)

I think a LOT of it is because you can drink ethanol and get drunk. If you drink methanol, you get dead. So the increased price of ethanol is to discourage people from buying it really cheap and getting drunk off of it. In reality, ethanol is one of the cheapest chemicals out there.

In high school we were taught to always think of AAA when dealing with acid. (Always Add Acid).

True, but it's debateable as to whether or not yellow phosphorus is a true allotrope, or just a mixture of white and red phosphorus. Black phosphorus is a true allotrope, however, which has been verified by its chemical reactivity and structure.

"Nonionic" means 'no ions'. So a nonionic substance is a substance which is not composed of ions. This would be things like carbon dioxide, water, ethanol, sugar, graphite, methane, benzene, etc. etc. Ionic substances are generally salts. (I.E. sodium chloride, silver nitrate, calcium carbonate, etc. etc.)