What's the gas that makes the moist red litmus blue?

What's the gas that makes the moist red litmus blue?

In high school, the gas that makes the wet red litmus blue is ammonia NH3

In high school, the gas that turns the wet red litmus paper blue is ammonia NH3

What is the difference between red litmus and blue litmus What is the difference between red litmus and blue litmus and purple litmus? What is the difference between red litmus and blue litmus What's the difference between red litmus and blue litmus and purple litmus?

You can think of litmus paper as white, acidified red, used to test alkali, it turns blue, while blue litmus paper is alkali-treated, used to test acid.