I think this is the correct answer for Arrange the following aqueous solutions, all at 25 C in order of decreasing acidity?
Knowing 2 things, lower pH, stronger acid. Low as in around 1-3 on pH scale, now this is easy.
KOH...in water it becomes K+ and OH-. OH- is a STRONG base, very high pH.
pOH = 14-pH. So pOH = 8.55 means pH = 5.45, same as the other