Solid State

What fraction of one edge centred octahedral void lies in one unit cell of fcc?

1. 13
2. 14
3. 112
4. 12

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). In the light of the above statements, choose the most appropriate answer from the options given below :

1. Both (A) and (R) are correct and (R) is the correct explanation of (A)
2. Both (A) and (R) are correct but (R) is not the correct explanation of (A)
3. (A) is correct but (R) is not correct
4. (A) is not correct but (R) is correct

Copper crystallises in fcc unit cell with cell edge length of 3.608 10-8 cm. The density of copper is 8.92 g cm-3. Calculate the atomic mass of copper.

1. 63.1 u
2. 31.55 u
3. 60 u
4. 65 u

Match List-I with List-II : Choose the correct answer from the options given below :

1. (a)-(iv), (b)-(iii), (c)-(i), (d)-(ii)
2. (a)-(i), (b)-(ii), (c)-(iii), (d)-(iv)
3. (a)-(i), (b)-(iii), (c)-(ii), (d)-(iv)
4. (a)-(iv), (b)-(iii), (c)-(ii), (d)-(i)

What fraction of Fe exists as Fe(III) in Fe0.96O ? (Consider Fe0.96O to be made up of Fe(II) and Fe(III) only)

1. 120
2. 112
3. 0.08
4. 116

The correct option for the number of body centred unit cells in all 14 types of Bravais lattice unit cells is :

1. 3
2. 7
3. 5
4. 2

Right option for the number of tetrahedral and octahedral voids in hexagonal primitive unit cell are :

1. 12, 6
2. 8, 4
3. 6, 12
4. 2, 1

An element has a body centered cubic (bcc) structure with a cell edge of 288 pm. The atomic radius is :

1. 24 288 pm
2. 4 3 288 pm
3. 4 2 288 pm
4. 34 288 pm

A compound is formed by cation C and anion A. The anions form hexagonal close packed (hcp) lattice and the cations occupy 75\% of octahedral voids. The formula of the compound is :

1. C3A4
2. C4A3
3. C2A3
4. C3A

Iron exhibits bcc structure at room temperature. Above 900°C, it transforms to fcc structure. The ratio of density of iron at room temperature to that at 900°C (assuming molar mass and atomic radii of iron remains constant with temperature) is

1. 3 2
2. 4 33 2
3. 3 34 2
4. 12