(a) The pH values of six solutions A to F are given below :

A = 0, B = 11, C = 6, D = 3, E = 13, F = 8

Which of the above solutions are

(i) acids

(ii) alkalis?

25 What does the pH of a solution signify? Three solutions A, B and C have pH values of 6, 4 and 10 respectively. Which of the solutions is highly acidic? 25 A farmer has found that the pH of soil in his fields is 4.2. Name any two chemical materials which he can mix with the soil to adjust its pH. 26 Name the acids or alkalis used to make (i) car batteries (ii) explosives (iii) soaps (iv) fertilizers. 27 The pH of a cold drink is 5. What will be its action on blue and red litmus solutions?