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
(a) neutral?
(b) strongly alkaline?
(c) strongly acidic?
(d) weakly acidic?
(e) weakly alkaline?
Arrange the pH in increasing order of hydrogen-ion concentration.

Explanation

(i) Neutral (pH = 7), (ii) Strongly acidic (pH = 1), (iii) Strongly alkaline (pH= 11), (iv) Weakly alkaline (pH = 9), (v) Weakly acidic (pH = 4).
Please note that higher the pH of solution, lesser will be `H^(+)` ion concentration. In the light of the above information, the pH values in increasing order of `H^(+)` ion concentration is `:(iii)lt(iv)lt(i)lt(v)lt(ii).`