litmus paper

The best way to confirm that the solution is neutralized is with litmus paper.

Watson recalls one telling advertising campaign: posters printed on litmus paper that said: “When acid rain is falling, you should see red” – offering a vivid illustration of the problem.

Mr. Bradford views them as economic litmus papers for the poorest parts of the city, as companies laid off workers and stimulus checks ran out.

Testing kits come in all shapes and sizes, but when working with kids, it’s best to use a simple litmus paper test.

You have three basic options: a pH testing kit that uses litmus paper or an electronic pH tester, or you can send a soil sample into a lab.