Question

A neutral solution turns litmus paper from _____ to _____.
A. red, blue
B. blue, red
C. yellow, red
D. none of these

Answer 1

Hint: The litmus paper is a type of acid-base indicator used to detect the acidity and alkalinity of the solution. The pH less than 7 is acidic solution, the pH more than 7 is basic solution and the neutral solution has pH 7.

Complete step by step answer: Litmus paper test is a method which uses litmus paper to detect whether the solution is acidic in nature, basic in nature or neutral in nature. When any substance is dissolved in water and litmus paper is dipped in the solution, the change in color helps to predict the alkalinity and acidity of the solution.
The pH of the solution is defined as the negative logarithm of hydrogen ion concentration. The pH scale ranges from 0 to 14. When the pH of the solution is less than 7, then the solution is considered as an acidic solution. When the pH of the solution is more than 7, then the solution is considered as a basic solution. When the pH of the solution is 7, then the solution is considered as a neutral solution.
When blue litmus paper is dipped in acidic solution, the litmus paper changes its color from blue to red. When red litmus paper is dipped in the basic solution, the litmus paper changes its color from red to blue. The neutral solution does not change the color of the litmus paper.
So, the correct answer is “Option D”.

Note:
The neutral litmus paper is purple in color. The neutral solution is formed from mixing strong acidic solution and strong basic solution therefore it is neutral in nature.