NTA Abhyas JEE Main2020ChemistrySolid StatePractice
Calculate the number of unit cells present in a cube-shaped ideal crystal of N a C l of mass 1.00 g [Atomic masses: N a = 23 , C l = 35.5 ]
Options
- A2.57 × 1 0 21 unit cells
- B5.14 × 1 0 21 unit cells
- C1.28 × 1 0 21 unit cells
- D1.71 × 1 0 21 unit cells
Correct answer
A. 2.57 × 1 0 21 unit cells
Step-by-step solution
Number of NaCl unit in one gram = 1 58.5 × 6.023 × 1 0 23 = 1.029 × 1 0 22 A unit cell contains 4 N a + ion and 4 C l - ions Unit cell = 1.029 × 1 0 22 4 = 2.57 × 1 0 21 unit cell