Question

In the following $NaCl$ type structure:

Salt	Anion-anion distance	Cation-anion distance
MT	$2.40\mathring{A}$	$1.70\mathring{A}$
MQ	$1.63\mathring{A}$	$1.15\mathring{A}$
RT	$2.66\mathring{A}$	$1.88\mathring{A}$
RQ	$2.09\mathring{A}$	$1.48\mathring{A}$

$MT$ is represented as:

• A.
• B.
• C.
• D.

Answer 1

Answer: (A)

The difference in internuclear distance between $MT$ and $RT$ indicates that the cations must not be touching all the anions in $MT$. Thus the structure of $MT$ is