Division 4.1 F1

Silica gel with a grain size of between 0,063 and 0,200 mm (70/280 mesh) prepared as follows: Place the silica gel in a porcelain capsule, dry in an incubator at 160 °C for four hours, then leave to cool at room temperature in a desiccator. Add water equivalent to 5 % of the mass of the silica gel as follows: Weigh 152 g silica gel into an Erlenmeyer flask then add 8 g of distilled water, stopper and shake gently to distribute the water evenly. Leave to stand for at least 12 hours before use.