After the reactants have been weighed out in the required amounts, they are mixed. For manual mixing of small quantities, usually an agate mortar and pestle are employed. Sufficient amount of some volatile organic liquid – preferably acetone or alcohol – is added to the mixture to aid homogenization. This forms a paste which is mixed thoroughly. During the process of grinding and mixing, the organic liquid gradually volatilizes and has usually evaporated completely after 10 to 15 minutes. For quantities much larger than ~20g, mechanical mixing is usually adopted using a ball mill and the pro