posted by mohammed .
the consentration of Sr(OH)2 I
S 0.02 WHAT IS THE CONSENTRATION OF OH ASSUMING COMPLETE DISSOCIATION
Concentration is the word you need.
if the molar concentration of Sr(OH)2 is .02M, then you have with complete dissociation .02M of Sr++, and .04M of OH-. Now why did the OH double? The reason is that in each molecule of Sr(OH)2 you had two OH ions.