The indicator methylene blue

Question

Is blue in an anaerobic environment
Is blue when oxygen is present
Is pink when oxygen is present
Absorbs excess oxygen

Answer 1

The indicator methylene blue plays a crucial role in determining the presence or absence of oxygen in a given environment. In an anaerobic environment where there is no oxygen, methylene blue appears blue in color. However, when oxygen is present, methylene blue turns pink. This color change occurs because methylene blue acts as a reducing agent and absorbs the excess oxygen molecules, thereby causing the indicator to change color. Hence, methylene blue is commonly used to indicate the presence of oxygen in various scientific experiments and processes.