Question

A solution turns red litmus blue, its pH is likely to be :
A. 1
B. 4
C. 5
D. 10

Answer 1

Hint: we know that the solution belongs pH <7 is acidic and the solution belongs pH >7 is alkaline or basic. We must have basic information that if the colour of litmus turns red then the solution is acidic and if the colour of litmus turns blue then the solution is basic

Complete step by step answer:
- the pH scale is in between $1$ to $17.$
- the solution which has pH more than $7$, the solution is likely to be basic or alkaline
- the solution which has pH less than $7$, the solution is likely to be basic
- the solution which has pH equal to $7$, the solution is likely to be neutral
- if a solution turns red litmus blue, then the solution is basic or alkaline
- if a solution turns blue litmus red, then the solution is acidic
- Red paper that does not change colour indicates the sample is an acid. Blue paper that does not change colour indicates the sample is a base
Hence the correct option is (D) $10.$

Additional Information:
Additional Data (in points)

Note:
students make sure to confirm that a solution which has ph above the 7 is alkaline and it converts red litmus blue or blue litmus remains blue. a solution which has ph below the 7 is acidic and it converts blue litmus red or red litmus remains red. The use of litmus paper is restricted only to the solution which has drastic difference between the value of the pH , for smaller changes or to identify the strength of the acid or base pH papers are generally used which have narrowed down pH depending on the color obtained.