Google Chrome is adding a slash to my searches

It's doing this because having a # in the URL usually means to link to a specific anchor on a page, because it is reading what you entered as a URL. For example the url:

http://superuser.com/questions/806272/.../806274#806274

Means link to the anchor name #806274. Chrome is trying to be helpful by adding in a slash to your URL because it thinks you may have missed it.

As far as I know there is no way to disable this action, other similar features can be found in the "privacy" portion of your settings, but none of them seem to have any affect. If you're so inclined, you can file an issue with Chromium to specify that this should not be the default behaviour (check to see if the issue exists on Chromium before filing the issue report though).

It looks like there was an issue opened recently in the Chromium issues list here, and there is a similar ongoing issue here for those who want to keep track.