##### Metallic rhodium crystallizes in a face-centered cubic lattice, with one Rh atom

 Chemistry Tutor: None Selected Time limit: 1 Day

Metallic rhodium crystallizes in a face-centered cubic lattice, with one Rh atom per lattice point. If the metallic radius of Rh is 134 pm, what is the volume of the unit cell in pm3 and in cm3?

pm3
cm3
Jun 2nd, 2015

When you hear face-centered cubic (FCC), the edge length is 3*root(2) times the radius.

The edge length on your second problem is length=radius*(3root2)=568pm. So the volume is 568^3=1.83x10^8 pm^3

pm^3 to cm^3, divide it by 10^30,

So it's 1.83x10^-22 cm^3

1.83x10^8 pm^3--------------------cm^3

1.83x10^-22 cm^3

1.83x10^8 pm^3-

Jun 2nd, 2015

That was so wrong heres the answer

For a face-centered cubic lattice with one atom per lattice point, there are4 atoms per unit cell.
The atoms are in contact along a face diagonal and 4r = (2)1/2a, where r is the metallic radius and a is the edge length of the cell.

Thus: a = r / 0.354 = 134 pm /0.354 = 379 pm

For a cubic cell the volume is the edge length cubed.
V = (379 pm)3 = 5.44E7 pm3

1 pm = 10-12m = 10-10cm

1 pm3 = 10-30cm3

 5.44E7 pm3 =  5.44E-23 cm3

Jun 2nd, 2015

okay dear, iam so sorry that i did not get it right..........................................

Jun 2nd, 2015

you see how its done?

Jun 2nd, 2015

...
Jun 2nd, 2015
...
Jun 2nd, 2015
Dec 8th, 2016
check_circle