Answer
An increase or decrease of one pH unit will always change [H$_{3}$O$^{+}$] concentrations by a factor of 10. Therefore, a pH of 3 will be ten times more acidic than a pH of 4, as a change of one pH unit has occurred.
Work Step by Step
An increase or decrease of one pH unit will always change [H$_{3}$O$^{+}$] concentrations by a factor of 10. Therefore, a pH of 3 will be ten times more acidic than a pH of 4, as a change of one pH unit has occurred.
