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.
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.
haha okay thank you so much
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.
oh k thanks
No, pm and ppm are not the same thing. "pm" stands for picometer, which is a unit of length equal to one trillionth (10^-12) of a meter. On the other hand, "ppm" stands for parts per million, which is a unit of concentration.
To convert picometers (pm) to centimeters (cm), you need to use the fact that there are 100 centimeters in a meter. Therefore, there are 10^-2 meters in a centimeter.
To convert pm to cm, you can use the following conversion factor:
1 pm = 10^-12 meters
1 meter = 100 centimeters
Multiplying these conversion factors together, we get:
1 pm = (10^-12 meters) * (100 centimeters/1 meter)
Simplifying, we get:
1 pm = 10^-10 centimeters
So, to convert a length from picometers to centimeters, you can multiply the length by 10^-10.
In your case, you have an edge length of 5.88 x 10^2 pm. To convert this to centimeters, you can multiply it by the conversion factor:
5.88 x 10^2 pm * 10^-10 cm/pm
Simplifying, we get:
5.88 x 10^2 pm * 10^-10 cm/pm = 5.88 x 10^-8 cm
Therefore, the edge length in centimeters is 5.88 x 10^-8 cm.