Question

Why tertiary alkyl halides when treated with sodium ethoxide does not produce ether but alkene?

Answer 1

Here is your answer;

When the tertiary alkyl halide treated with  sodium ethoxide, the product is an alkene but not ether.

What happens is that the tertiary alkyl halide normally undergo the SN1 and E1 process to give substitution products.

The substituted product is the most stable hence predominates