[chrisaltman]

...cells in Liters?
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Hi all- new to the forum. I'm at NYU in some really tough Chem and Bio courses, so I figured I'd get some help from the masses. Thank you in advance!
In Silberberg's Chemistry, there is a problem that states:

The Volume of a bacterial cell is 2.54 micrometers^3. What is the volume of the cell in millimeters?
-This computes to 2.54*10^-9 mm^3, because you add the exponents (they're on the same scale; meters).
  The back of the book verifies that this is correct. However, part (B) of the question asks,

What is the volume of 10^5 cells in Liters?

I've done the calculation a million times, but I must be setting it up wrong. I establish that one cell in Liters has a mass of 2.54*10^-15 g, but from there I get stumped. The back of the book gives the answer as 10^-10 Liters. How does this make sense?! Any help is greatly appreciated.

[Borek]

You don't need mass. All you need is number of mm³ in L.

[chrisaltman]

You don't need mass. All you need is number of mm³ in L.

I don't need the mass. Okay. So, do I use Avogadro's Number here? It's asking for the volume of 10^5 cells that each have a volume of 2.54^3 micrometers. Could someone clarify?

[Borek]

No, you are just converting volumes.

[chrisaltman]

Sorry, none of that information is helpful in the least.

[Borek]

mm³ is a volume unit, just like L. Conversion between mm³ and L is similar to conversion between - say - cups and gallons. You have to know how many cups in gallon and you are ready. In this case you have to know how many mm³ in L.