- Litmus paper is typically blue in neutral or basic solutions (pH 7 or higher).
- The blue color indicates the presence of hydroxide ions (OH-) in the solution.
- The deeper the blue color, the more basic the solution.
Some common substances that might turn litmus paper blue include:
- Baking soda (sodium bicarbonate)
- Soap or detergent
- Toothpaste
- Antacids
- Certain cleaning products
