Are bezene,  toulene etc. Are common names? If so,  what are thier iupac names? 

Do you have any thoughts? Do you know the difference between a common / trivial name and IUPAC nomenclature? 

Do you mean benzene and toluene?  What is the reason for your question?

i learnt naming polycyclic compounds recently. i was curious about the naming of napthlene. but internet didn't give any iupac name for it.

 

 

 

16 minutes ago, muskan said:

napthlene.  but internet didn't give any iupac name for it.

 

Perhaps if you spelled it correctly?   Naphthalene

 

Does this help?

 

Yep, there's the problem!   You are misspelling the "common names". 

If you look up "benzene", not "bezene", you will find that Its "IUPAC" name is "benzene"!

If you look up "toluene", not "toulene", you will find the "IUPAC" name is "methylbenzene".

And, finally if you look up "naphthalene" rather than "naphthalene", you will find that the "IUPAC" name is, again, "naphthalene".

(The "systematic IUPAC name" (I confess I don't know that that means) can be "Bicyclo[4.4.0]deca-1,3,5,7,9-pentaene" or "Bicyclo[4.4.0]deca-2,4,6,8,10-pentaene").