Question: HOw are some acids stronger than others?

Rebecca Dewey answered on 22 Jun 2015:

The strength of an acid refers to its ability or tendency to lose a proton (H+), and this is often called the pH. A pH of 7 is considered neutral (no tendency to lose a proton). Acids are all things with a pH less than 7. So a strong acid is very likely to lose protons very quickly, and could have a pH less than zero (although it gets so strong that it becomes difficult to measure accurately).

The other thing to consider is concentration. That isn’t about the chemical’s tendency to lose protons, but instead is just about *how much* of the chemical you have. A high concentration acid could have a pH of nearly 7 (i.e. fairly neutral) but could be quite strong because you’ve got a lot of it!