Question

How could a strong acid have the same pH as a weak acid?

Answer 1

Because strong and weak refer to their tendency to form `H^+` ions, not the concentration of those ions.

Explanation:

pH is a measure of the concentration of hydrogen ions (something like `log_10[H^+]` if memory serves, but I’d check that before quoting me ... it was 30 years ago I did this.)

Strong and weak are descriptors used to indicate how readily the acid dissociates into ions, one of which will be hydrogen. Strong acids dissociate more readily, so will often contribute to a lower pH, but it isn’t the same thing.