1) can't use a beaker measuring liquid.
(2) should be on asbestos online heating, make its heat evenly; When heated, the outer wall of the beaker should have no water droplets.
(3) liquid when heated, not more than a beaker for two-thirds of the volume, is a beaker half of the volume.
(4) in the process of solvent or thinner, stirring with a glass rod, don't touch the bottom of the glass or cup
量液体用量筒