MHT CET202618 April 2026Evening ShiftChemistrySolid StateActual
A metal forms fcc structure. Calculate the volume of fcc unit cell in cm ^3 if void volume is 1.66 10⁻²³ cm ^3 .
Options
- A4.912 10⁻²³ cm ^3
- B8.151 10⁻²³ cm ^3
- C9.346 10⁻²³ cm ^3
- D6.385 10⁻²³ cm ^3
Correct answer
D. 6.385 10⁻²³ cm ^3
Step-by-step solution
For an fcc (face-centered cubic) structure, the packing efficiency is 74 % . The percentage of void volume in the fcc unit cell is 100 % - 74 % = 26 % . Let the total volume of the unit cell be V . Void volume = 0.26 V 0.26 V = 1.66 10⁻²³ cm ^3 V = 1.66 10⁻²³ 0.26 cm ^3 V = 6.3846 10⁻²³ cm ^3 6.385 10⁻²³ cm ^3 Answer: 6.385 10⁻²³ cm ^3