Question

Some 2-methyl-2-butene may be produced in the reaction as a by-product. Give a mechanism for its production.

Answer 1

We can't draw pictures on the board; even if we could you didn't give the reaction.

Answer 2

This sounds like an elimination reaction problem, in which case the answer is usually a discussion of E1 v E2 so see

http://en.wikipedia.org/wiki/Elimination_reaction