Suppose we add zero one mo of HCL to our one liter system. Let's see the new PH. Well, the PH is equal to negative log zero one, and that gives us a PH of two. That means if we add this little hydrochloric acid, our PH drops by five increments. That's equivalent to a 100,000 fold increase in the hydronium concentration of our mixture. So now let's add the same amount of sodium hydroxide, a base to our system.