Question

Silver crystallises in fcc lattice. If edge length of the cell is 4.07 x 10⁻⁸ cm and density is 10.5 g cm⁻³, calculate the atomic mass of silver.

Answer 1

Dear Student,

● Answer -

M = 106 g/mol

◆ Explanation -

# Given -

a = 4.07x10⁻⁸ cm

d = 10.5 gcm⁻³

# Solution -

Formula for density of crystal structure is given by -

d = Z.M / a³.NA

M = d.a³.NA / Z

M = 10.5 × (4.07x10⁻⁸)³ × 6.022×10²³ / 4

M = 106 g/mol

Therefore, molecular mass of silver is 106 g/mol.

Thanks dear...

Answer 2

Explanation:

Diameter of the sphere = 28 cm

Thus, radius of the sphere = 28/2 = 14 cm

Diameter of cone = 14/3 cm

Thus, radius of the cone = 14/3 / 2

radius of cone = 7/3

Volume of the sphere = 4/3πr³

Volume of cone = 1/3πr²h

Number of cones = Volume of sphere/Volume of cone

= (4/3 × 14 × 14 × 14)/(1/3 × 7/3 × 7/3 × 3)

= 10976 × 9/147

= 672

Therefore, the number of cones so formed is 672.