How many effective Na + and Cl - ions are present respectively in a unit cell of NaCl solid (Rock salt structure) if ions along line connecting opposite face centres are absent?

Question

How many effective Na + and Cl - ions are present respectively in a unit cell of NaCl solid (Rock salt structure) if ions along line connecting opposite face centres are absent? (A) 3,3 (B) (7/2), 4 (C) (7/2), (7/2) (D) 4, (7/2)

Tardigrade Admin · Accepted Answer

Number of Na +=4-1=3 Number of Cl -=4-2 × (1/2)=3

Q. How many effective $N a^{+}$ and $C l^{-}$ ions are present respectively in a unit cell of $N a Cl$ solid (Rock salt structure) if ions along line connecting opposite face centres are absent?

3,3

$\frac{7}{2}, 4$

$\frac{7}{2}, \frac{7}{2}$

$4, \frac{7}{2}$

Number of $N a^{+} = 4 - 1 = 3$

Number of $C l^{-} = 4 - 2 \times \frac{1}{2} = 3$

Q. How many effective Na+ and Cl− ions are present respectively in a unit cell of NaCl solid (Rock salt structure) if ions along line connecting opposite face centres are absent?

3,3

27​,4

27​,27​

4,27​

Number of Na+=4−1=3 Number of Cl−=4−2×21​=3

Q. How many effective $N a^{+}$ and $C l^{-}$ ions are present respectively in a unit cell of $N a Cl$ solid (Rock salt structure) if ions along line connecting opposite face centres are absent?

$\frac{7}{2}, 4$

$\frac{7}{2}, \frac{7}{2}$

$4, \frac{7}{2}$

Number of $N a^{+} = 4 - 1 = 3$

Number of $C l^{-} = 4 - 2 \times \frac{1}{2} = 3$