Glass stoppers should be held between in the middle and ring fingers as shown in the picture. You should never lay it on the lab bench top and then put it back in the bottle as it can transfer contaminants to the rim of the bottle, and ultimately into the contents of the bottle.
Droppers with rubber bulbs are commonly used to transfer small volumes of liquids. Here you can see the student is carefully adding sulfuric acid, drop by drop, to a small test tube. NOTE: DO NOT turn droppers or pipets with any kind of rubber bulb upside down. The liquid will run down into the bulb, either contaminating the liquid and/or ruining the bulb.
	Berel pipets can easily be weighed by first taring (zeroing) a small beaker and then placing the filled pipet in the beaker.
The potassium permanganate should be added dropwise, slowly, with stirring after every few drops. The pink/purple color will disappear quickly at first, then require more stirring.
	The endpoint of the hydrogen peroxide-potassium permanganate titration is a light pink color. It occurs when all of the peroxide has been used up in reducing the manganese in the permanganate ion to the colorless manganese(II) ion so that the next amount of permanganate is not reduced and thus the color remains pink.

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