A graduate student preforms two reactions in order to make some new ethers. In the first reaction the student mixes 3-chloro-2-methylprop-1-ene and methanol and in the second the student mixes 4-chloro-2-methylbut-1-ene with methanol. The next day the student examines the reaction and finds that one has completely finished and the other is not even 10% complete. Which reaction has completely finished? Why?