Question

In $NaCl$ crystal each $C{l}^{-}$ ion is surrounded by

• A. $4N{a}^{+}$ ions
• B. $6N{a}^{+}$ ions
• C. $1N{a}^{+}$ ions
• D. $2N{a}^{+}$ ions

Answer 1

Answer: (B)

$NaCl$ has octahedral structure.

In $NaCl$ crystal, $C{l}^{-}$ ions adopt cubic close packed arrangement and $N{a}^{+}$ ions occupy all the octahedral sites. Therefore, $Na$ and $Cl$ have $1:1$ stoichiometry. In other words, each $N{a}^{+}$ ion is surrounded by six $C{l}^{-}$ ions which are disposed towards the corners of a regular octahedron. Similarly, each $C{l}^{-}$ ion is surrounded by six $N{a}^{+}$ ions.