Answer to Question #144780 in General Chemistry for Joshua

Question

Tungsten metal crystallizes with a body-centered cubic unit cell. The volume of the cell is 0.0317 nm^3. A) what is the atomic raduis of tungsten in cm? B) what is the volume of a single tungsten atom? C) what is the density of a single tungsten atom?

Answer 1

a. Edge l ength = (3.16 × 10^-9m³) ^⅓ = 3.16 × 10^-4 m

atomic radius = √3/ 4 × 3.16 × 10^-4 m = 1.37 × 10^-4 m = 0.0137cm

b. Volume = 4/3 πr³ = 4/3 × π × 0.0137³ = 1.08 × 10^-5 cm³

c. Find the mass of 2 atoms . Molar mass of tungsten = 184

2 × 184 / (6.02×10^-23) = 6.113 × 10^-22

Density = 6.113 ×10^-22÷ (1.08 × 10^-5) = 5.660 × 10^-20g/cm³