Question

Five solutions, A, B, C, D and E, when tested with universal indicator, showed pH as 4, 1, 11, 7 and 9, respectively. Which solution is

1. neutral?
2. strongly alkaline?
3. strongly acidic?
4. weakly acidic?
5. weakly alkaline?

Arrange the pH in increasing order of hydrogen-ion concentration.

Answer 1

1. Neutral → Solution D with pH 7.
2. Strongly alkaline → Solution C with pH 11.
3. Strongly acidic → Solution B with pH 1.
4. Weakly acidic → Solution A with pH 4.
5. Weakly alkaline → Solution E with pH 9.

The pH can be arranged in the increasing order of the concentration of hydrogen ions as pH = 11 < pH = 9 < pH = 7 < pH = 4 < pH = 1.