[subu]

Which one is more stable: a 1° carbocation or a 1°carbanion? Why? On a similar note, which one is more stable: a 3° carbocation or a 1° carbanion? Again, why?

[Dan]

Please read the Forum Rules - you must show you have attempted the question.

The answer to these questions can be found in any organic chemistry textbook. Googling would give you the answer in seconds. You need to do the legwork yourself.

[subu]

Actually, I meant CH3(-) vs CH3(+) instead of 1°.
I was going to raise a discussion. I am not working on any assignments.

[orgopete]

Which one is more stable: a 1° carbocation or a 1°carbanion? Why?

Actually, I cannot think of any instance in which a molecule could form an anion or cation. Although I believe energetically the carbanion is lower in energy, that would not make it more likely to form than a carbocation in a reaction of CH3Cl with AlCl3.

On a similar note, which one is more stable: a 3° carbocation or a 1° carbanion? Again, why?

I think the more appropriate question is which is more stable, CH3(-) or Me3C(-) and why? Here, I'll give a hint. It is CH3(-). Why? If you can answer this, you should be able to answer which cations should be more stable.

[ABA2015]

as I know delocalization of the charge can make the cation or anion more stable so 3° carbocation is more stable than 1°