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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 ]

1. 5.14 × 10²¹ unit cells
2. 1.28 × 10²¹ unit cells
3. 1.71 × 10²¹ unit cells
4. 2.57 × 10²¹ unit cells

Correct answer: 2.57 × 10²¹ unit cells

Solution

The correct option is derived by calculating the number of moles of NaCl in 1.00 g, which is then multiplied by Avogadro's number to find the total number of unit cells, as each unit cell corresponds to one formula unit of NaCl.

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