What are the duties of the Vice President?

Officially, the Vice President takes over for the President whenever the need arises. Unofficially, the Vice President does whatever the President wants him to do. During the previous administration, the VP was the President. During the current administration, the VP just hangs around.

since every state has 2 senators, the framers of the constitution saw that it was possible for there to be an even split in voting for laws. so it is the duty of the VP to cast a tie-breaking vote. however the constitution never envisioned "filibuster" or super majority to pass bills, they assumed that 50% plus one vote was all that is ever required. The republicans have filibustered over 100 times in the last term making a "tie" vote a moot point. The Tea Party does not actually believe in government as envisioned by the constitution, that is cynical just lip service.

His role is not very well-defined so it depends on the president.

Bush gave Cheney a lot of power. Other VPs have been reduced to little more than figures sent to cut ribbons and schmooz with people.

Officially the VP is the "leader of the Senate" although in reality that is not the case, since the majority Senate leader is the one who actually runs things.

The vice president is actually the leader of the Senate but is only used to break ties in the legislature and take the place of the president if God forbid anything happened to him.

I have to agree with master answer, the vice president has no power except to take place as the president if something happens to him. Until then he just owns up to the president.

to be pet of Obama