system
Given the following post, respond as if you're commenting on Reddit:
human
Is there a limit to how acidic (or basic) something can be?

I have heard of an acid with a pH of -24. Can anything go past that? What about alkaline compounds?
gpt
The way we calculate pH is by taking the concentration of H^+ ions in a solution and inputting it in this formula:

pH = -log[H^+ ] 

So in theory as long as the concentration of H^+ is high enough negative pH is possible. The same goes for alkaline compounds (though there you're concerned with the concentration of OH^- ). 

The problem comes in practical applications. Measuring a negative pH is very difficult as the glass detectors can't measure the very low  pH correctly and will therefor return higher values of pH than might actually be there. Further complicating matters is the facts that at very high concentrations even the stronger acids (for example HCl) don't fully dissociated (release their H^+ ) so calculating the pH from the concentration of HCl wouldn't yield the correct pH either. 

In short, theoretically there is no maximum to how high or low a pH can go, in practice, you'll find yourself limited in being able to measure the actual very low or high pH's and less than full dissociation at high concentrations.