If it's less than 1.0
times ten to seven, it's basic. Likewise, if our hydroxide concentration is less than 1.0 times six, negative seven, it's an acidic solution. If it's more than 1.0 times six mega seven, it's a basic solution. Now, in this last step, I want to look at the expression for kw again. And my goal is to take this expression and convert it to this expression. This expression will be convenient when we know the PH and we want to find the poh.