Pipet vs Buret???

[Xtian]

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These two questions seem to contradict, please explain:

Q: An organic chemist wanted to deliver 15.6ml of a liquid in an experiment. Which should she employ?

graduated cylinder
buret
pipet
volumetric flask
condenser

ans: a pipet is calibrated to deliver a specific volume of liquid when filled to the mark and allowed to drain. The buret will deliver known volumes of solution, but during a titration.

Q: A student wanted to measure exactly 12.3ml of a 0.2M NaOH solution. Which should she use?

transfer pipet
buret
soxhlet extractor
graduated cylinder
volumetric flask

Ans: since the student wanted to measure exactly 12.3ml, an odd vol, a buret would be best. Pipets allow transfer of accurately known volumes from one container to another. The precision that you get from a buret is much greater than a pipet.

 

[xhamburgersamx]

These two questions seem to contradict, please explain:

Q: An organic chemist wanted to deliver 15.6ml of a liquid in an experiment. Which should she employ?

graduated cylinder
buret
pipet
volumetric flask
condenser

ans: a pipet is calibrated to deliver a specific volume of liquid when filled to the mark and allowed to drain. The buret will deliver known volumes of solution, but during a titration.

Q: A student wanted to measure exactly 12.3ml of a 0.2M NaOH solution. Which should she use?

transfer pipet
buret
soxhlet extractor
graduated cylinder
volumetric flask

Ans: since the student wanted to measure exactly 12.3ml, an odd vol, a buret would be best. Pipets allow transfer of accurately known volumes from one container to another. The precision that you get from a buret is much greater than a pipet.

I think it has to do with the wording of the question. In the 2nd one, it says "exactly 12.3mL" therefore you want an instrument that is precise and accurate which a buret usually is and it involves NaOH which is a classic base used in titration. The first question says transferring of a liquid which is possible with pipets (they vary in size). You wouldn't normally use a buret in liquid transfers not involving titrations. That's my opinion but I understand why these questions contradict I feel the same way.

 

[doc toothache]

These two questions seem to contradict, please explain:
Q: An organic chemist wanted to deliver 15.6ml of a liquid in an experiment. Which should she employ?
graduated cylinder
buret
pipet
volumetric flask
condenser

ans: a pipet is calibrated to deliver a specific volume of liquid when filled to the mark and allowed to drain. The buret will deliver known volumes of solution, but during a titration.
Q: A student wanted to measure exactly 12.3ml of a 0.2M NaOH solution. Which should she use?
transfer pipet
buret
soxhlet extractor
graduated cylinder
volumetric flask
Ans: since the student wanted to measure exactly 12.3ml, an odd vol, a buret would be best. Pipets allow transfer of accurately known volumes from one container to another. The precision that you get from a buret is much greater than a pipet.

In the second question pipette would be the correct answer, except that it is not a choice. Transfer pipettes are simply medicine drops. The explanation should have qualified that they were referring to transfer pipettes since it is inaccurate to state that burettes are more precise than pipettes, considering the fact that it is possible to use a micropipette to deliver as little as 1 microliter.

 

[Contach]

interesting

 

[O Gaúcho]

So if one of the answers was a volumetric pipet would that be the correct answer? Since it has the highest precision?