Summary: The solution is considered acidic when: [1] pH < 7. [2] pOH > 7. [3] [H+] > 10-7 [4] [OH-] < 10-7 The solution is considered basic when: [1] pOH < 7. [2] pH > 7. [3] [OH-] > 10-7 [4] [H+] < 10-7