JEE Main2003ChemistrySolid StateActual
How many unit cells are present in a cubeshaped ideal crystal of NaCl of mass 1.00 ~g ? [Atomic masses: Na =23, Cl =35.5 ]
Options
- A5.14 10²¹ unit cells
- B1.28 10²¹ unit cells
- C1.71 10²¹ unit cells
- D2.57 10²¹ unit cells
Correct answer
D. 2.57 10²¹ unit cells
Step-by-step solution
Number of formulas in cube shaped crystals = 1.0 58.5 6.02 10²³ since in NaCl type of structure 4 formula units form a cell unit cells = 1.0 6.02 10²³ 58.5 4 =2.57 10²¹ unit cells.