when would you need to use pipettes instead of graduated cylinders or volumetric flasks?

Answer 1

For accurate measurement of smaller volumes. Graduated cylinders are useful for volumes down to 10-25 ml, but become more difficult to accurately read. Volumetric flasks go down to as low as 5 ml, but for readings lower than this, you need either glass volumetric pipettes or automatic pipetters, which can go down to the microliter level.

Answer 2

Pipettes hold very small volumes, like only 10-30ml. Graduated cylinders are a little larger, they would hold like 500ml, and volumetric flasks are the largest, they could hold 1-2 liters.

Answer 3

You use a bulb pipette because it's far more accurate then a graduated cylinder or volumetric flask. You use it by simply squeezing the blue pipette bulb and once the liquid gets to the fill line you cover it with your finger and transfer it to where you want it.