Question

I posted this up yesterday:

I have to use the equation :

density= mass/ volume:

But i don't know how to find out the volume using the edge length of the unit cell which is 5.88* 10^2 pm.

CHemistry....Please help - DrBob222, Sunday, January 25, 2009 at 10:41pm

If the edge length is 5.88 x 10^2 pm, first convert that to cm, then cube that to find the volume in cc.
The mass of a unit cell is (4 x molar mass)/6.022 x 10^23.

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I understand how to do it but the problem is i don't know how to convert pm to cm...i googled it and I'm not able to find it and in the textbook it doesn't tell me either...is it the same thing as ppm.

Answer 1

5.88E2pm (1m/E12pm)=5.88E-10m(E2cm/1m)
= 5.88E-8cm

Now another way to do this is paste this in your google search engine...
5.88E2pm in cm

Or if you just want to be lazy and let google do the volume directly, you can type

(5.88E2pm)^3 in cm^3

or if you just want to be real lazy, you can let Google do the entire thing for you..type in
mass/(side in pm)^3 in g/cm^3
(like this
30kg/(5.88E2pm)^3 in g/cm^3

and viola.

Answer 2

haha okay thank you so much

Answer 3

Bob Pursley showed you lazy ways and th real way but sometimes you don't have google by your side. Just remember that 1 pm = 10^-12 meters, then convert to cm.

Answer 4

oh k thanks