Which one of the following has minimum value of cation/anion ratio ?

Options

A. NaCl
B. KCl
C. `MgCl_(2)`
D. `CaF_(2)`.

Answer

C

Explanation

Size of cation
`Mg^(2+)(72 p m) lt Ca^(2+)(100 p m)ltNa^(+) (102 p m) lt K^(+) (138 p m)`
Size of anion. `F^(-)(133 p m) lt Cl^(-)(184p m)`
Size of cation/anion will be minimum when size of cation is minimum and size of anion is maximum (i.e. `Mg^(2+)//Cl^(-)`) i.e., in `MgCl_(2)`.