A teacher gave two test tubes to the students, one containing water and the other containing sodium hydroxide.
Q. A teacher gave two test tubes to the students, one containing water and the other containing sodium hydroxide. She asked them to identify the test tube containing sodium hydroxide solution. Which one of the following can be used for the identification?
- Blue litmus
- Red litmus
- Sodium carbonate solution
- Dilute hydrochloric acid
Answer: Red litmus