Here's why:
* Sodium chloride is a neutral salt. This means it doesn't have acidic or basic properties. It forms when a strong acid (hydrochloric acid) reacts with a strong base (sodium hydroxide), resulting in a neutral solution.
* Litmus paper is used to test for acidity and alkalinity. Red litmus paper turns blue in basic solutions and stays red in acidic or neutral solutions.
Since sodium chloride is neutral, the red litmus paper will remain red.
