In an Sn1 reaction, the reagents are 2-methyl-2-butanol and hydrochloric acid and its product is 2-chloro-2-methyl butane. The experiment's percent yield is only 64%.

Provide reasons why the yield for the experiment was less than 100%. These reasons may include incomplete reactions (explain why), side reactions (show how these could take place) or potential technical limitations (heating/mixing/cooling/etc). Explain how you could improve the yield.