QJEEM21Chbd95: JEE Main 2021 Chemistry - Class 12 JEEM21Chbd95 Solution: Ga (atomic mass 70 u) crystallizes in a hexagonal close packed…

Question

Verified Solution • 2025–26 Session moderate

Ga (atomic mass 70 u) crystallizes in a hexagonal close packed structure. The total number of voids in 0.581 g of Ga is __________

\times

10²¹. (Round off to the Nearest Integer). [Given : N_A = 6.023

\times

10₂₃]

Accepted Answer

For HCP structure Z = 6

Tetrahedral Void = (Z

\times

2) = 12

Octahedral Void = [Z

\times

1] = 6

No. of void per unit cell = 18

No. of unit cell =

\left( {{{0.581 \times {N_A}} \over {70 \times 6}}} \right)

No. of void =

\left( {{{0.581 \times 6.023 \times {{10}^{23}}} \over {70 \times 6}}} \right) \times 18

= 14.99 \times {10^{21}}

Step-by-Step Verified Solution