Question

A unit cell of NaCl has 4 formula units. Its edge length is 0.50 nm. Calculate the density if molar mass of NaCl = 58.5 g/mol.

Options

• 1 g/cm³

• 2 g/cm³

• 3 g/cm³

• 4 g/cm³

Answer 1

3 g/cm³ 

Explanation:

Using formula,

Density = `(("Z" xx "m")/("a"^3 xx "Na"))`

D = `(4 xx 58.5)/((0.5 xx 10^-7) xx 6.023 xx 10^23)`

= 3.1 g/cm³