MHT CET202521 Apr 2025Evening ShiftChemistrySolid StateActual
Calculate the volume of fcc unit cell in cm ^3 if void volume of it is 4.16 10⁻²⁴ ~cm ^3 .
Options
- A1.3 10⁻²³
- B1.6 10⁻²³
- C4.1 10⁻²³
- D5.8 10⁻²³
Correct answer
B. 1.6 10⁻²³
Step-by-step solution
The void volume in an FCC unit cell relates to the total volume through the packing efficiency. With a packing efficiency of 74 % , the void fraction is 1 - 0.74 = 0.26 . Given V_ void = 4.16 10⁻²⁴ , cm ^3 , the unit cell volume follows as V_ unit cell = V_ void 0.26 . V_ unit cell = 4.16 10⁻²⁴ 0.26 = 1.6 10⁻²³ , cm ^3 This corresponds to option B .