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161. A metal (at. mass = 50) has a bcc crystal structure. The density of the metal is 5.96 g cm^–3. Find the volume of its unit cell?

Solution:
We have given that
Atomic mass of the metal = 50g
bcc unit cell, Z = 2
Density of metal = 5.96 g/cm³Therefore, volume of the unit,

a^{3} = \frac{M \times Z}{N_{A} \times d} = \frac{50 \times 2}{6.02 \times 10^{23} \times 5.96} = 2.787 \times 10^{- 23} {cm}^{3}

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162. Calculate the density of silver which crystallizes in a face centred cubic lattice with unit cell length 0.4086 nm (At. mass of Ag = 107.88)

306 Views

Long Answer Type

163. An element crystallizes in a structure having a fcc unit cell of an edge 200 pm. Calculate its density if 200 g of this element contains 24 x 10²³ atoms.

1254 Views

164. An element X with an atomic mass of 60 g/mol has density of 6.23 g/cm^–3. If the edge length of its cubic unit cell is 400 pm, identify the type of cubic unit cell. Calculate the radius of an atom of this element.

1420 Views

Short Answer Type

165. An atom has fcc crystal whose density is 10 gm^–3 and cell edge is 100 pm. How many atoms are present in its 100 g?

2031 Views

Long Answer Type

166. Analysis shows that a metal oxide has the empirical formula M_0.98 O_1.00. Calculate the percentage of M²⁺ and M³⁺ ions in this crystal.

Or

In an ionic compound the anion (N) form cubic close type of packing. While the cation (M⁺) ions occupy one third of the tetrahedal voids. Deduce the empirical formula of the compound and the coordination number of (M) ions.

904 Views

167. An element E crystallizes in body centred cubic structure. If the edge length of the cell is 1.469 x 10^–10 m and the density is 19.3 g cm^–3, calculate the atomic mass of this element. Also calculate the radius of this element.

422 Views

168. Calculate the efficiency of packing in case of a metal crystal for
(i) simple cubic
(ii) body- centred cubic
(iii) face - centred cubic . (With the assumptions that atoms are touching each other).

315 Views