12-07715. Pole Reagent Paper [Archived]

Description and references

Unsized paper impregnated with a soln of 1-2 g phenolphthalein in 10 ml alcohol and 110 ml water and then passed, while still wet, through a soln of 20 g Na2SO4 (cryst) in 100 ml water; the paper is then dried.

Use

For recognizing the negative poles of batteries (the reaction at the negative pole coloring the paper red). The ends of the wires are placed about 1/2 inch apart on the moistened paper.

Status

This monograph has been retired and is no longer subject to revision or update.