A unit cell of sodium chloride has four formula units. The edge length of the unit cell is 0.564 nm. What is the density of sodium chloride ?

Options

A. `1.2 g cm^(-3)`
B. `2.16 g cm^(-3)`
C. `3.64g cm^(-3)`
D. `4.56 g cm^(-3)`

Answer

B

Explanation

Density `= ( Z xx M )/( a^(3) xx N_(A))`
`= ( 4 xx 58.5)/(( 5.64 xx 10^(-8) cm)^(3) xx 6.022 xx 10^(23))`
`= 2.16 g cm^(-3)`