So I'm in my first Chem course and I think I've got a pretty good understanding on polar bonds but I'm confused about non-polar bonds which my Professor just barely glazed over in our lecture. What atoms might form a non-polar bond with each other and how does their bond work?
A polar bond occurs when there is a difference in electro-negativity between two bonded atoms. For example, H-Cl will, as Cl is more electronegative that H, have the electrons “pulled” slightly from the H towards the Cl, this type of bond is opposed to the Cl-Cl bond, as there is no net change in electro-negativity, electrons are merely shared and not attracted to one side or the other!
I keep getting confused when naming compounds since all the rules I find are different or too wordy. Can you just state the rules simply? I know there is a difference when naming ionic, binary and molecular compounds which is really what is throwing me off? keeping track of them all. If not, can you link me to a tutorial if you know one? THANK YOU SO MUCH (finals this week!)
This is so clever - CanvasMol is a 3-D molecule viewer made entirely with HTML5!
Jmol is used by a lot of chemists to embed 3-D models into web pages, but it uses Java. I can’t stand it because it’s ugly, quirky, often crashes my browser (regardless of whether I’m using Firefox or Safari on a Mac or PC) and uses loads of system resources. I hope Jmol dies out and is replaced with this.
Response to Question: How can food irradiation treatments assure us that our food won’t, well, fill us up with free radicals and the like?
Food irradiation is carried out with Gamma-emitters, meaning gamma-rays (high energy electromagnetic radiation) are emitted. These have the effect of killing bacteria and the like from the food, however, Gamma-emitters do not cause much ionisation, as they are (mainly) not particles. As such, they do not form many free radicals, and hence, make our food safe to eat, as well as give it a longer shelf life.
The carborane superacid H(CHB11Cl11), which is one million times stronger than sulfuric acid, is entirely non-corrosive, whereas the weak acid hydrofluoric acid (HF) is extremely corrosive.
Hydrofluoric acid is best known to the public for its ability to dissolve glass by reacting with SiO2 (silicon dioxide), the major component of most glass, to form silicon tetrafluoride gas and hexafluorosilicic acid. This property has been known since the 17th century, even before hydrofluoric acid had been prepared in large quantities by Scheele in 1771.
Because of its high reactivity toward glass, hydrofluoric acid must be stored (in small quantities) in polyethylene or Teflon containers. It is also unique in its ability to dissolve many metal and semimetaloxides.
Submission: I just learned why smoking in gas stations is prohibited.
It’s because of the gasoline. Wait, don’t stop here — it seems obvious, but what makes it explode is NOT the liquid gasoline.
Liquid gasoline doesn’t even burn. Some people has already even tried a trick to put out match fires with gasoline, and it worked. What burns is the vapor off the gasoline, reacting with the oxygen in the air. That vapor is highly flammable.
When ignited with a simple bit of fire, the vapor will burn in a chain reaction and oxygen will power the fire. If it is in an enclosed space, the heat will pressurize the container and whatever holding it will burst out violently into pieces when it can’t stand the pressure anymore.
Submission: Check out this cheat sheet I made for Org II
I’m trying to put together the definitive blog for people taking sophomore organic chemistry. Still have a lot of work/improvement to do but it’s gaining steam. This past few days I spent some serious time putting together what I think is the definitive cheat sheet for carbonyl chemistry. Everything is on it - the Aldol. Claisen, Michael, Fischer esterification… etc. It’s set up logically, with electrophiles along the Y axis and nucleophiles on the X - together there’s 110 different cells. The cool thing is that although there’s all these different types of reactions, they can all be boiled down to a sequence of only 5 different mechanistic steps - protonation/deprotonation, 1,2-addition, 1-2-elimination, 1-4 addition, and SN2. Plus at the bottom there’s another 13 reactions that don’t fit so well in the table.
Geckos, nature’s supreme climbers, can race up a polished glass wall at a meter per second and support their entire body weight from a wall with only a single toe. But the gecko’s remarkable climbing ability has remained a mystery since Artistotle first observed it in the fourth century B.C.
Working at Lewis & Clark College, the University of California at Berkeley, the University of California at Santa Barbara, and Stanford University, the interdisciplinary team:
• confirmed speculation that the gecko’s amazing climbing ability depends on weak molecular attractive forces called van der Waals forces,
• rejected a competing model based on the adhesion chemistry of water molecules, and
• discovered that the gecko’s adhesive depends on geometry, not surface chemistry. In other words, the size and shape of the tips of gecko foot hairs—not what they are made of—determine the gecko’s stickiness.
Dihydrogen Monoxide (DHMO) is a colorless and odorless chemical compound, also referred to by some as Dihydrogen Oxide, Hydrogen Hydroxide, Hydronium Hydroxide, or simply Hydric acid. Its basis is the highly reactive hydroxyl radical, a species shown to mutate DNA, denature proteins, disrupt cell membranes, and chemically alter critical neurotransmitters. The atomic components of DHMO are found in a number of caustic, explosive and poisonous compounds such as Sulfuric Acid, Nitroglycerine and Ethyl Alcohol.