Why does aqueous ch3nh2 turn litmus paper blue

Answer 1

Bases turn red litmus blue. CH3NH2 is a base; therefore, it turns litmus paper blue.
Why is it a base? First it is a base because of definition. By the Bronsted theory it is a base because it accepts a hydrogen ion from H2O. CH3NH2 + H2O ==> CH3NH3^+ + OH^- Second reason when it reacts with water you see it produces a OH^- ion. By the Arrhenius definition the production of an OH^- ion makes it a base.