You can directly support Crash Course at http://www.subbable.com/crashcourse Subscribe for as little as $0 to keep up with everything we're doing. Also, if you can afford to pay a little every month, it really helps us to continue producing great content. In this episode, Hank goes over Reversible Reactions, the water dissociation constant, what pH and pOH actually mean, Acids, Bases, and Neutral Substances as well as the not-so-terrifying Logarithms, strong acids, weak acids, and how to calculate pH and pOH. Oh, and litmus paper! ***** AND NOW, A SUBBABLE MESSAGE! ***** "Daisy, we love you more than you love John and Hank! From Mum and Nemo." -- Table of Contents Reversible Reactions 3:40 Water Dissociation Constant 5:00 Acids, Bases, & Neutral Substances 6:38 Strong and Weak Acids 7:43 Logarithms 1:46 Calculating pH and pOH 8:45 Cool Mathematical Connections 9:54 -- Want to find Crash Course elsewhere on the internet? Facebook - http://www.facebook.com/YouTubeCrashCourse Twitter - http://www.twitter.com/TheCrashCourse Tumblr - http://thecrashcourse.tumblr.com Support CrashCourse on Subbable: http://subbable.com/crashcourse