2009 adea sample test question

[dental deezle]

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If a chemist needed to measure 12.52 ml of solution. the best piece of laboratory equipment is?

C. Pipet
D. Buret

Answer: D. Buret

Destroyer 2010 Ochem # 154

An Organic Chemist wanted to deliver 15.6 of a liquid in an experiment, which should she employ?

B. Buret
C. Pipet
Answer : C. PiPet


can someone explain this?

 

[Trojantwc]

I believe what they had in mind when they thought of pipettes were the plastic, bulbed ones without markings. Like those we often used and threw away in bio labs. Compared to those, a buret would have been significantly more accurate.

These days, most of the pipettes we use for chem labs are the calibrated ones with detailed markings along the side.

 

[Teenythainy]

I'm confused. Graduated pipettes and pipettes with the disposable tips are extremely precise. Are they not referring to those? In lab, measuring with a buret, unless you're titrating, is more inconvenient than a pipet.

 

[JLT223]

http://www.gcsescience.com/aa30.htm

 

[Teenythainy]

http://www.gcsescience.com/aa30.htm

But there are different types of pipet. Do we just assume they're referring to the 1 measurement volumetric pipet?

 

[JLT223]

But there are different types of pipet. Do we just assume they're referring to the 1 measurement volumetric pipet?

I'd just know that pipettes, in general, are used to transfer a measured volume of liquid. On the other hand, a burette dispenses a variable, measured amount of a chemical solution. You don't need to know any more than that.