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
neutral?
Solution D is neutral (pH = 7).
strongly alkaline?
Solution C is strongly alkaline (pH = 11).
strongly acidic?
Solution B is strongly acidic (pH = 1).
weakly acidic?
Solution A is weakly acidic (pH = 4).
weakly alkaline?
Solution E is weakly alkaline (pH = 9).
Explanation
The textbook explains that the pH scale measures from 0 to 14, where pH 7 is neutral, values less than 7 are acidic, and values more than 7 are basic/alkaline. The further the pH is from 7, the stronger the acid or base. Solution D (pH 7) is exactly neutral. Solution B (pH 1) is strongly acidic as it is very close to 0 on the scale. Solution A (pH 4) is weakly acidic as it is less than 7 but not extremely low. Solution C (pH 11) is strongly alkaline as it is closer to 14. Solution E (pH 9) is weakly alkaline as it is greater than 7 but not extremely high.