KCl crystallises in the same type of lattice as does NaCl Given that `r_(Na^(+))//r_(Cl^(-))=0.55` and `r_(K^(+))//r_(Cl^(-))=0.74`, the ratio of the side of unit cell for KCl to that of NaCl is

Options

A. `1.123`
B. `0.891`
C. `1.414`
D. `10.414`

Answer

A

Explanation

`(r_(Na^(+)))/(r_(Cl^(-)))=0.55, (r_(K^(+)))/(r_(Cl^(-)))=0.74`
`therefore (r_(Na^(+)))/(r_(Cl^(-)))+1=1.55 " "` ….(1)
`(r_(K^(+)))/(r_(Cl^(-)))+1=1.74 " "` ….(2)
Dividing (2) by (1), `(r_(K^(+))+r_(Cl^(-)))/(r_(Na^(+))+r_(Cl^(-)))=(1.74)/(1.55)=1.122`