Question

An an ionic crystal of ab to type crystallises in fluoride style with density 6.45 gram per mole edge length of unit cell is 400 and strong if all the islands lying on a body are removed from all the unit cell then what will be the new density b

Answer 1

Answer:

Answer

Calcium fluoride has cubic structure, where each Ca

2

+ ion (cation) is surrounded by 8 F

−

ion and each F

−

ion (anion) is surrounded by 4 Ca

2

+ ions. So the coordination number of Ca

2

+ is 8 and coordination number of F

−

is 4.

Therefore, in case of AB

2

(which have similar crystal structure with CaF

2

), coordination number of A

2

+ is 8 and coordination number is B

−

is 4.

Rock salt has a cubic crystal structure. Here Na

=

and Cl

−

have FCC structure . Both cation and anion are surrounded by 6 oppositely charged ions. So the coordination number of each Na

+

(cation) and Cl

−

(anions) is 6.