What are the using techniques of chemical reagents?

First condition for the uses of chemical reagent is that reagent should be taken as small amount as possible. Before using the reagents user have to know about the composition of the reagents, bad effect of produced wastage, natural disturbance and long time radio active effect. Level have to be observed in the apparatus before using the reagents in the laboratory. Correct composition have to be taken, validity and preservation date have to be known. Essential and enough safety should be taken before using the reagent if there are any accident. Water never be added to the concentrated acid. In this case acid is added to the water drop wise and stirred it continuously. Dropper of a reagent bottle should not changed with the other.