The pH is a measure of the H+ ion concentration. The lower the pH the greater the concentration of hydrogen ions this means the lower the pH the stronger the acid. The higher the pH the greater the concentration of hydroxide ions this means the higher the pH the stronger the base. Look at a pH scale below:

Question	Answer
Which of the substances above are acids?	Interactive popup. Assistance may be required. Check Your Answer Vinegar and bananas Close
Which of the substances above are bases?	Interactive popup. Assistance may be required. Check Your Answer ammonia and drain cleaner Close
Of the acids, which acid dissociates more?	Interactive popup. Assistance may be required. Check Your Answer Vinegar Close
Of the bases, which base dissociates more?	Interactive popup. Assistance may be required. Check Your Answer drain cleaner Close