[Hubert]

what's the difference between aprotic and protic? and btw wat's carbocation intermediate? need an answer asap..thanks

[Qazzian]

Protic/Aprotic are usually used to describe solvents. A protic solvent is one that has hydrogens that can be donated, like H2O (can become H+ and OH-). H+ is a proton, hence the name, "Protic". Aprotic means that it does not have these protons. An example is ether. These solvents don't give off hydrogens.

A carbocation intermediate is an intermediate compound that a reaction goes through, which has a positive charge on a carbon. intermediates are the high point of a reaction energy diagram. You should also learn the stability of carbocations, as they're going to be pretty useful as you go on.

Hope this helps.

[Donaldson Tan]

Qazzian:  :thmbup:

protic and aprotic solvents can affect reaction pathways. organic protic solvents (eg. propanol) deactivate nucleophiles. Nucleophiles are typically negatively-charged, so the electropositive 'head' of the solvent can bond to the nucleophile, thus making it bulky, ie. kinetic hindrance.

eg. if u reflux chloroethane with potassium tert-butanoxide in propanol (protic solvent), you will yield ethene (elimination). if you reflux chloroethane with potassium tert-butanoxide in tetrachloromethane (aprotic solvent), you will yield an ether (nucleophillic substitution)

hope this is helpful