This document discusses how to prepare a 0.1% active chlorine solution from commercial bleaching powder. It explains that bleaching powder is composed of calcium hypochlorite (Ca(ClO)2) and calcium chloride hypochlorite (Ca(ClO)Cl) with a total chlorine content of around 50-27%. To make a 0.1% solution, 3 grams of bleaching powder should be dissolved in 1000mL of water, producing a 3000ppm solution, or 0.1% active chlorine. Alternative methods are provided if a weighing scale is not available.