explain the electrophilic addition mechanism?
364997
Electrophilic addition is where a electrons from a ring, or other unsaturated system (ie an alkene/alkyne) attack an electropositively charged species, for example in the bromination or nitration of benzene to yield bromobenzene or nitrobenzene respectively.  If you draw the mechanism for these reactions you will be able to see more clearly what the electrophilic mechanism is.\n\nAn electropositive species is for example an acid chloride (where the carbonyl imparts the electropositivity), bromine (where the Br-Br bond becomes polarised in the presence of a multiple bond), iso(thio)cyanates (where the carbonyl imparts the electropositivity), nitration reactions (NO2+) etc etc.\n\n"Electrophilic" means "electron loving", so to form a bond with these electrophilic molecules requires you to donate electrons.  In the bromination of benzene, the electrons are donated from the ring to the Br2 molecule, and aromaticity is briefly lost.  The Br-Br bond breaks, forming a new C-Br bond and Br-.  A positive charge remains on the benzene ring, which is lost by the re-formation of a double bond by the Br- removing the acidic proton.\n\n"Nucleophilic", which is the opposite, means "nucleus loving", therefore these species contain additional electrons which they want to donate to the nucleus of the other species.\n\nWith the exception of radical chemistry, all chemical reactions involve and electrophile and a nucleophile.\n\nI hope this helps someway.\n\nI found the link below which may give a better description.
525723
when an atom loses an electon from its outermost shell then it forms an electropositive ion while when an atom gains an electron it forms an electronegative elctron.\n\nfor e.g. during the formation of nacl na atom loses an elcron to the cl atom to form a +ve ionwhile the cl atom which gains that electon forms a -ve ion.
815531
It is simply sum of products minus sum of reactants\n\n[H2O + N2] - [O2 + NH3]\n\nSince this is a 1 to 1 ratio reaction, the coefficients are one. (if there was a coefficient for NH3, you must multiply the enthalpy value of NH3 by that # because that is how many moles you have, and the value given is for only one mole.)
1076966
pardon me, but why is this in chemistry?
664298
molecular: \nHCl + K2CrO4 + SnCl2 --> CrCl3 + SnCl4 + KCl + H2O\n\nnet ionic: H+ + CrO42- + Sn2+ --> Cr3+ + H2O + Sn4+\n\nreduction half reaction: \n3 e- + 3 H+ + 5 HCl + K2CrO4 --> CrCl3 + 2 KCl + 4 H2O\noxidation half reaction:\n2 HCl + SnCl2 --> SnCl4 + 2 H+ + 2 e-\n\nBalancing them:\n6 e- + 6 H+ + 10 HCl + 2 K2CrO4 --> 2 CrCl3 + 4 KCl + 8 H2O\n6 HCl + 3 SnCl2 --> 3 SnCl4 + 6 H+ + 6 e-\n-----------------------------------------------------------\n6 H+ + 16 HCl + 2 K2CrO4 + 3 SnCl2 --> 2 CrCl3 + 4 KCl + 8 H2O + 3 SnCl4
956728
1-Propanol. CH3CH=CH2 + B2H6 ===> CH3CH2CH2-BH2 ===> CH3CH2CH2-OH.\n\nDiborane always adds with the H on the more highly substituted carbon. This is the opposite of the Markovnikov rule during reaction with H2O and a little H2SO4, where the H goes to the less highly substituted carbon to give 2-propanol.
669383
This depends on what you do to the concentrations.  If you increase the concentration of the solution that contains the ion that gets reduced, you will increase the voltage based on LeChatelier's principle and collision theory.  If you increase the other solution, containing the ion that gets oxidized, you will decrease the voltage, by increasing the reate of the reverse reaction (again according to LeChatelier and collision theory).
870926
in order of increasing stability: 1, 2, 3.\n\nThe hyperconjugative and inductive effects are complimentary to each other and can not be mutually excluded.  \n\nThe empty P orbital on the carbocation interacts with the neighboring C-H sigma bonds resulting in transfer of electron density and formation of pi-bond character between the carbocation carbon and neighboring carbons.  This is the hyperconjugative effect.  The more neighbors you have, the more sharing can happen and the more stable the carbocation is.\n\nAttraction of electron density to the positively charged carbon results in induced dipoles between the carbocation carbon and its neighbors.  This allows for delocalization of the positive charge away from the carbocation carbon to its neighbors.  The neighbors become somewhat electron deficient due to electrons density herding toward the carbocation.  The more neighbors you have the more carbons the positive charge can be delocalized to and the more stable the carbocation.\n\nThe attraction of electron density referred to in the inductive argument is the partial pi bond formation in the hyperconjugation argument.
744884
it is called electrolysis\n2NaCl + 2H2O ----> 2NaOH  + H2 + Cl2
889022
sterics help the water to attack the central carbonyl, as the other 2 are crowded by the phenyl ring. and with the electronics of the system the central carbonyl is the most electropositive making it a great target for nucleophilic addition
897106
I don't know if this is what you're looking for but... E1 reactions are caused by the solvent pulling off the leaving group, thus a carbo-cation is produced. The leaves the door open for rearrangement of the carbon skeleton, you'll often see alkyl and hydride shifts in the intermediate (carbons and hydrogens moving around to stabilize the atom). E1 is usually preformed in reflux conditions (boiling point of the solvent), which also makes carbon rearrangement more likely. E1 is also in competition with Sn1 (which isn't an elimination at all), so you'll get rearmaments at chiral centers, alkyl halides, and other trash. So E1 kinda messes with your product. \n\nBut, your other option, E2, requires antiperiplanar geometry when removing the other hydrogen, so rings are a whole mess by themselves. And E2 is not great for removing OH groups, you usually have to protonate the OH (usually with acid) and make an oxonium ion (positive oxygen) and get the OH to leave as H2O, which is an E1 mechanism. Man, organic chem is a pain.
1012268
You may need to refer to Maxwell's distribution of molecular energies for this. Every reaction has its own specified activation energy which is the maximum amount of energy with which reacting molecules must collide to overcome the Ea barrier to form products. For some reactions, the Ea is very high and the molecules, in standard conditions, don't have enough internal energy needed to overcome that barrier - that's why they require a stimulus like the presence of light, to provide them with more internal energy.\n\nA catalyst acts in the same way, but unlike light which provides energy, it simply lowers the Ea for the reaction. The result is that the internal energy which the reactants possess is enough to get them through the barrier when they collide. Think of it as hurdles in a race being shortened down so that it's easier for the athletes to jump. With a lower Ea, more number of reacting molecules are able to cross the barrier per unit time, whereas if the Ea was not lowered, only a few molecules might gain the high Ea required and cross it, while the rest won't reach the transition state.\n\nBut the alternative transition state only has a lower Ea when you introduce a catalyst. In the presence of light, Ea will be the same, but the reacting molecules will get extra energy.
740866
The ethoxide ion. By the positive inductive effect, the alkyl group releases electrons to the O- portion of the ion. Remembering that bases are proton acceptors, it is easy to see that the greater negative charge will make it easier to accept the proton.
399371
Basically, when you rub two certain materials, you will create static electricity, which is named that way because the charges do not _flow_, i.e. there is no current.\n\nNot so basically, but still very primitively, there exist two forms of material: ones that "likes" to "steal" electrons, and ones that "likes" to "give" electrons. Whenever these two are put next to each other, the electrons "jump" from one substance to the other, causing a potential difference, and possibly a spark (if the potential difference is high enough).\n\nRubbing two such materials does not cause this effect. It is a common misconception; when you rub two things you are simply increasing the surface area of contact between the two such substances, thereby creating a more noticeable effect.\n\nand the check spelling button screwed up some of my spelling. fix it yahoo! people, please. especially with the word 'effect' which was changed to 'effectt' and the plural of some words.
220779
For benzene to undertake this addition reaction, it must be subject to heat (323K) and approx 400atm pressure.  In direct sunlight alone, there may be no reaction.  Addition of a catalyst drives electrophilic substitution towards C6H5CL + HCL
328575
reduction:  2e- + Cu2+ --> Cu      Eo = +0.34 V  cathode (+)\n\noxidation:   Zn   --> Zn2+ + 2e-   Eo = +0.76 V    anode (-)\n________________________________________\n\nZn  + Cu2+ --> Cu  +  Zn2+         Eo = +1.10V therefore cell spontaneous as written.
1053808
Gee, I know you're a student but you are dull and lazy.\n\nHaven't you heard of google??  \n\nStep 1 - I went to www.google.com\nStep 2 - I used the following search  "electroclorination +equation"\n\nhttp://www.google.com/search?hl=en&lr=&q=electrochlorination+%2Bequation\n\nStep 3 - I followed the first link (listed below) on the google.com search results.\n\nAnd you've waited how many days for this answer?  It took me less than one minute to find.