Question

.6. X-ray diffraction studies show that
copper crystallises in an fcc unit cell
with cell edge of 3.608 x 10-8 cm. In
a separate experiment, copper is
determined to have a density of
8.92 g cm-3. Calculate the atomic
mass of copper.​

Answer 1

Answer:

Use the formula

Explanation:

d=z into m/a cube into n

Answer 2

Answer :

• Atomic mass of copper = 63.1 u.

Step-by-step explanation :

Given that,

• Edge length of unit cell = $\bold{3.608\times{}10^{-8}\:cm}$

• Density of copper = $\bold{8.92\:g/cm^3}$

$\hrulefill$

For fcc lattice, Z = 4.

Also, we know, $\bold{\rho=\dfrac{Z\times{}M}{a^3\times{}N_0}}$

$\implies\bold{M=\dfrac{\rho\times{}a^3\times{}N_0}{Z}}$

Hence,

$\bold{M=\dfrac{(8.92\:g\:cm^{-3})(3.608\times{}10^{-8}\:cm)^3(6.022\times{}10^{23}\:atoms\:mol^{-1})}{4\:atoms}}$

$\implies\bold{63.1\:g\:mol^{-1}}$

∴ Atomic mass of copper = 63.1 u.