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

Options

A. KCl
B. NaCl
C. `CaF_2`
D. `MgCl_2`

Answer

C

Explanation

Among the three options KCl, NaCl and `MgCl_2` , the size of anion is same. So larger the cation, larger will be the cation/anion ratio i.e., KCl will have larger cation/ anion ratio among the three. So, we left with two options KCl and `CaF_2` . Among these two `CaF_2` will have maximum value of cation/anion ratio because decrease in ionic radii of anion from `Cl^-` to F does not overcome the effect of decrease in ionic radii of cation from `K^+` to `Ca^(2+)`