Asked in
Black Holes

Why look for black precipitate in the butt instead of on the surface of an H2S test?


User Avatar
Wiki User
November 24, 2012 6:43AM

The black precipitate usually sink to the bottom which the reaction took place in.

The reaction takes place at the bottom because it only occurs under anaerobic conditions, and it does not sink to the bottom as it only occurs at the bottom, not around oxygen at the top of the tube.