∵pH=−log [concentration] Therefore, for change in one unit of pH, concentration must be changed to 10 times pH=−log(10−1) pH=log‌10=1 If pH‌‌=3‌ , then ‌ 3‌‌=−log‌10−x 3‌‌=x‌log‌10⇒x=3 Thus for change in concentration (ie dilution) to get 3 times of pH, the solution must be diluted to 100 times, 1θ