Question

A solution turns red litmus blue, its pH is likely to be
(a) 1 (b) 4 (c) 5 (d) 10

NCERT Class 10th Science Chapter 2 Acids Bases and Salts

Answer 1

LIKELY TO BE 10.................
BECause 1,4,5 it is all acid and 10 is a base
               as we know that red litmus blue  means basic in nature
so the rt ans is10

Answer 2

A solution turns red litmus blue, its pH is likely to be 10.
Because the solution is base,so it turns red litmus to blue.
pH of base is greater than 7.