Question

Assertion:If the length of the unit cell of `LICI` having `NaCI` structure is `5.14 Å `, the ionic radius of `CI^(-)` ion is `.82 Å`
Rason : Anion- anion contact is retaned in`LiCI` structure because anion constitute the lattice
A. If both assertion and reason are true and the reason is the correct explanation of the assertion
B. If both assertion and reason are true but reason is not the correct explanation of the assertion
C. If assertion is true bur reason is false
D. If assertion is false bur reason is true

Answer 1

Correct Answer - a
If anion -anion contact is retaired , then as shown in the adjoining figure

interionic distance `LiCI= a//2 = 5.14Å//2 = 2.57 Å`
`BC = sqrt(AB^(2) + AC^(2)) = sqrt((2.67)^(2) = (2.57)^(2)) = 3.63 Å`
Radius of `CI^(-) ion = (1)/(2) BC = (1)/(2) xx 3.63 = 1.81 Å`
Hence reason is the correct explanation of assertion