Students can test solutions for acid or base determination. Easy-to-use red litmus paper turns blue for bases and blue litmus turns red for acids. 100 strips of each. Not for measuring the pH of natural waters, such as streams, rivers and lakes. To measure pH in these waters, try our Water Chemistry Test Strip, pH 6-9, item 652729 or, for a wider pH range, our LaMotte Water test kit, item 652927, pH 3.0-10.5.
