Weak acids and bases ionize partially; strong acids and bases ionize 100%. Strong and weak have nothing to do with how corrosive the acid/base is. Therefore, we can have concentrated solutions of weak acids (15M acetic acid) or dilute solutions of weak acids (0.001M acetic acid). Conversely we may have concentrated solutions of strong acids (12 M HCl) or dilute solutions of strong acids (0.001M HCl).
