Description: 80 strips per unit Alkali-base indicator paper strips When red litmus paper is placed in a substance that is alkaline (PH > 8.3), it will turn to blue However, if placed in a substance that is basic or neutral, it will remain red Note: Not for measuring the pH of solutions Specification: Paper Length: about 6cm Color: Red For chemistry experiments and school teaching. Package Includes: 80 Pieces Red Litmus Papers in one pack Note: Store in cool, dry place, keep it out of the sun. Not for measuring the pH value of solutions