Copper crystallises in fcc unit cell with cell edge length of 3.608 × 10-8 cm. The density of copper is 8.92 g cm -3. Calculate the atomic mass of copper.

Question

Copper crystallises in fcc unit cell with cell edge length of 3.608 × 10-8 cm. The density of copper is 8.92 g cm -3. Calculate the atomic mass of copper. (A) 65 u (B) 63.1 u (C) 31.55 u (D) 60 u

Tardigrade Admin · Accepted Answer

d =( Z × M / N A × a 3) 8.92=(4 × M /6.022 × 1023 ×(3.608 × 10-8)3) M =(8.92 × 6.022 × 1023/4) × 46.96 × 10-24 M =63.1 g / mol (Molar Atomic Mass) M =63.1 u (Atomic Mass)

Q. Copper crystallises in fcc unit cell with cell edge length of $3.608 \times 1 0^{- 8} c m$ . The density of copper is $8.92 g c m^{- 3}$ . Calculate the atomic mass of copper.

$65 u$

$63.1 u$

$31.55 u$

$60 u$

$d = \frac{Z \times M}{N _{A} \times a ^{3}}$
$8.92 = \frac{4 \times M}{6.022 \times 1 0 ^{23} \times ( 3.608 \times 1 0 ^{- 8} ) ^{3}}$
$M = \frac{8.92 \times 6.022 \times 1 0 ^{23}}{4} \times 46.96 \times 1 0^{- 24}$
$M = 63.1 g / m o l$ (Molar Atomic Mass)
$M = 63.1 u$ (Atomic Mass)

Q. Copper crystallises in fcc unit cell with cell edge length of 3.608×10−8cm. The density of copper is 8.92gcm−3. Calculate the atomic mass of copper.

65u

63.1u

31.55u

60u