Question

Arrange the following in increasing order of covalent character: $NaCl,MgC{l}_2,AlC{l}_3$.

• A. $NaCl<MgC{l}_2<AlC{l}_3$
• B. $MgC{l}_2<NaCl<AlC{l}_3$
• C. $AlC{l}_3<MgC{l}_2<NaCl$
• D. $NaCl<AlC{l}_3<MgC{l}_2$

Answer 1

Answer: (A)

$NaCl<MgC{l}_2<AlC{l}_3$

The covalent character is determined by polarisation as follows:-

$Covalentcharacter\alpha Polarisation\alpha \frac{Chargeoncation}{Sizeofcation}$

Note= When the charge difference exists in the compounds then we consider only the charge difference instead of the size of the cation.

So the charge on the cation is :

$Na$ = $+1$

$Mg$ = $+2$

$Al$ = $+3$

Aluminium has maximum charge.

So the correct option is [A]

$NaCl$<$MgC{l}_2$<$AlC{l}_3$