Question

Crystalline CsCl has density 3.988 g cm^-3. The volume occupied by single CsCl pair in the crystal will be ______.
(Molar mass CsCl = 168.4 g/mol)

Options

• 7.014 × 10^-3 cm³ 

• 7.014 × 10^-23 cm³ 

• 1.014 × 10^-3 cm³ 

• 1.542 × 10^-5 cm³ 

Answer 1

Crystalline CsCl has density 3.988 g cm^-3. The volume occupied by single CsCl pair in the crystal will be 7.014 × 10^-23 cm³.

Explanation:

CsCl forms SCC lattice (BCC type), Z = 1

Volume of unit cell = volume of single CsCl ion pair = a³

d = `("Z" xx "M")/("N"_"A" xx "a"^3)`

`=> "a"^3 = ("Z" xx "M")/("d" xx "N"_"A")`

`= (1 xx 168.4)/(3.988 xx 6.023 xx 10^23)`

7.014 × 10^-23 cm³