pH Indicator Test Paper, Wide Range can accurately test both acidic and basic conditions. Litmus is a water-soluble mixture of different dyes extracted from lichen. Dyeing filter paper either red or blue with this ink creates one of the oldest forms of testing alkalinity and acidity. Blue litmus paper turns red under acidic conditions and red litmus paper turns blue under alkaline conditions. Test range of these strips is 1-14 pH. The pH value of a neutral solution is 7.0. Solutions with a pH less than 7 are acidic and solutions with a pH greater than 7 are basic (alkaline). Packed conveniently, 10 books of 20 strips with the color indicator card printed on the lid of each strip and displayed on the plastic storage box.

• Wide range pH test strips, can test both alkalinity and acidity
• Ten books with 20 strips each
• Includes plastic storage case
• Color indicator on plastic storage case