Asked by Saira

How would i calculate the density of Li2S in grams per cubic centimeter?

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.

Answered by Saira
and how can i find out the mass m in grams of a unit cell of Li2S.

when the formula units in the unit cell for Li2S is 4.
Answered by DrBob222
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.
Answered by DrBob222
My answer for mass is for 4 atoms to the unit cell. I don't know if that's the same as 4 formula units per unit cell or not.
Answered by ElleSee
1.50g/cm^3