Question

In one sentence, how do you know if the glassware is clean?

In one sentence, why is a kimwipe tissue used to wipe the pipette?

Answer 1

1) Answer: Fill the glassware with distilled water and then empty it. If there are droplets visible on the side walls then we can say that it is not clean and if there are no water droplets observed, then we can say that it is clean.

Explanation: Glassware which is used and not cleaned will have contamination residue left behind on glass surface, which will not allow water to form a uniform layer on the surface, instead there will be droplets present. If glassware is cleaned then it becomes wettable.

2) Answer: Kimwipe tissue has characteristics such as 1) Low lint and low extractables, 2) fine soft, absorbent tissue resists scratching sensitive surfaces, 3) They are chemically inert, hence we can use it, not only with water but also other solvents and chemicals.

Explanation: we use pipetting for measuring liquid quantity with high precision. A small amount of contamination will give erroneous results. Hence it is important to wipe pipet with kimwipe.