The cubic unit cell of Al (molar mass 27 g mol-1 ) has an edge length of 405 pm. Its density is 2.7 text g text cm-3 . The cubic unit cell is

Question

The cubic unit cell of Al (molar mass 27 g mol-1 ) has an edge length of 405 pm. Its density is 2.7 text g text cm-3 . The cubic unit cell is (A) face centred (B) body centred (C) primitive (D) edge centred

Tardigrade Admin · Accepted Answer

Density (ρ )=(Z× M/a3× N0) 2.7=(Z× 27/(405× 10-10)3× 6.023× 1023) Z=(2.7× (405)3× 10-30× 6.023× 1023/27) =4 For face centred cubic unit cell, number of atoms are 4.

Q. The cubic unit cell of $A l$ (molar mass $27 g$ $m o l^{- 1}$ ) has an edge length of 405 pm. Its density is $2.7 g c m^{- 3}$ . The cubic unit cell is

face centred

body centred

primitive

edge centred

simple

Density $(ρ) = \frac{Z \times M}{a ^{3} \times N _{0}}$
$2.7 = \frac{Z \times 27}{( 405 \times 10 ^{- 10} ) ^{3} \times 6.023 \times 10 ^{23}}$
$Z = \frac{2.7 \times ( 405 ) ^{3} \times 10 ^{- 30} \times 6.023 \times 10 ^{23}}{27}$
$= 4$
For face centred cubic unit cell, number of atoms are 4.

Q. The cubic unit cell of Al (molar mass 27g mol−1 ) has an edge length of 405 pm. Its density is 2.7gcm−3 . The cubic unit cell is