Types of Unit Cell

Q.

in a crystalline solid, anions B are arranged in a cubic close packing. cations are equally distributed between octahedral and tetrahedral voids. if all the octahedral voids are occupied, what is the formula of the solid

Q.

Calculate the volume occupied by one molecule of water? (Given density 1 g cm^-3)

Q. The number of octahedral voids per lattice site in a lattice is (Rounded off to the nearest integer)

Q.

How do you calculate the number of ions in a solution?

Q. NUMBER OF MOLES OF TETRAHEDRAL VOIDS PRESENT IN FCC TYPE STRUCTURE HAVING 3 MOLES OF ATOMS IS

Q.

The volume of the HCP unit cell is

1. $24\sqrt{2}{r}^3$

2. $\frac{16}{\sqrt{2}}{r}^3$

3. $\frac{12}{\sqrt{2}}{r}^3$

4. $\frac{64}{3\sqrt{3}}{r}^3$

Q. $N{H}_{4}Cl$ crystallises in a body-centered cubic lattice with an unit cell edge length of 387 pm. The distance between the oppositely charged ions in the lattice is:

1. $83.77pm$
2. $274.46pm$
3. $335.15pm$
4. $137.23pm$

Q. The number of tetrahedral voids in the unit cell of a fcc lattice of similar atoms is

1. 4
2. 6
3. 8
4. 10

Q. The number of unit cells in 58.5g of NaCl is nearly

1. 6x10²⁰
2. 3x10²²
3. 1.5x10²³
4. 0.5x10²⁴

Q. An ionic solid crystallizes as rock salt structure(NaCl) and the edge lenghth of FCC unit cell having rock salt structure is 508pm. If the radius of cation is 110pm , then what is the radius of anion?

Q.

The cubic unit cell structure of a compound containing cation M and anion X is shown below. When compared to the anion, the cation has a smaller ionic radius. Choose the correct statement(s).

1. The empirical formula of the compound is $\mathrm{MX}$

2. The cation $\mathrm{M}$ and anion $\mathrm{X}$ have different coordination geometries

3. The ratio of $\mathrm{M}-\mathrm{X}$ bond length to the cubic unit cell edge length is $0.866$

4. The ratio of the ionic radii of cation $\mathrm{M}$ to anion $\mathrm{X}$ is $0.414$.

Q. In face centred cubic (fcc) crystal lattice, edge length of the unit cell is $400\text{pm}$. Find the diameter fo the greatest sphere which can be fitted into the interstitial void without distortion of lattice.

1. $200pm$
2. $117.2pm$
3. $141.4pm$
4. $70.7pm$

Q.

What is a primitive unit cell?

Q.

Distinguish between

(i)Hexagonal and monoclinic unit cells

(ii) Face-centred and end-centred unit cells.

Q.

Which one of the following schemes of ordering closed packed sheets of equal-sized spheres do not generate close-packed lattice?

1. ABCABC

2. ABACABAC

3. ABBAABBA

4. ABCBCACBC

Q.

Is a cell or an atom bigger?

Q.

What is the position of octahedral voids in FCC Unit cell?

1. Face center

2. body center

3. Edge center

4. corner

Q. An atom X crystallizes in fcc unit cell having an edge length $a=100\sqrt{2}pm$ . What would be the radius of tetrahedral void present in the unit cell?

1. $0.73pm$
2. $1.41pm$
3. $22.50pm$
4. $11.25pm$

Q. Metallic gold crystallises in a face centered cubic lattice of edge length $4.070\stackrel{o}{\text{A}}$. The closest distance between the gold atoms is:

1. $3.035\stackrel{o}{\text{A}}$
2. $8.140\stackrel{o}{\text{A}}$
3. $2.878\stackrel{o}{\text{A}}$
4. $1.357\stackrel{o}{\text{A}}$

Q.

What is the type of lattice structure of $\mathrm{NaCl}$?

Q. The spinel structure $\left(A{B}_2{O}_4\right)$ consists of an fcc array of $O^{2-}$ ions in which the

1. $A$ cation occupies one-eighth of the tetrahedral holes and the $B$ cations occupy half of the octahedral holes
2. $A$ cation occupies one-fourth of the tetrahedral holes and the $B$ cations occupy half of the octahedral holes
3. $A$ cation occupies one-eighth of the octahedral holes and the $B$ cations occupy one-fourth of the tetrahedral holes
4. $A$ cation occupies one-fourth of the octahedral holes and the $B$ cations occupy one fourth of the tetrahedral holes

Q. Given below are two statements :
Statements I: Potassium permanganate on heating at 573 K forms potassium manganate.

Statement II : Both potassium permanganate and potassium manganate are tetrahedral and paramagnetic in nature.

In the light of the above statements, choose the most appropriate answer from the options given below :

1. Both statement I and statement II are false
2. Both statement I and statement II are true
3. Statement I is true but statement II is false
4. Statement I is false but statement II is true

Q.

How many lattice points are there in one unit cell of each of the following lattice ?

(i) Face-centred cubic

(ii) Face - centred tetragonal

(iii) Body - centred

Q.

The total number of tetrahedral voids in the face centred unit cell is ................

(a) 6 (b) 8 (c) 10 (d) 12

Q.

A solid is made of two elements X & Z .the atoms Z are in CCP arrangement while atom X occupy all tetrahedral sites . what is the formula of the compound?

Q. The tetrahedral voids formed by ccp arrangement of $C{l}^{-}$ ions in rock salt structure are

1. Occupied by $N{a}^{+}$ ions
2. Occupied by $C{l}^{-}$ ions
3. Occupied by either $N{a}^{+}$ or $C{l}^{-}$ ions
4. Vacant

Q.

$N{H}_{4}Cl$ crystallizes in a body-centered cubic lattice with an edge length of unit cell equal to 387 pm. If the radius of the $C{l}^{-}$ ion is 181 pm, the radius for $N{H}_4^{+}$ ion is?

1. 154.1 pm

2. 92.6 pm

3. 366.3 pm

4. None of these

Q. An octahedral void is present at each edge of the FCC lattice. How much of each of these voids belong to each unit cell?

1. One-eighth
2. One-sixth
3. One-fourth
4. Half

Q. If a stands for the edge length of the cubic systems: simple cubic, body-centered cubic and face-centered cubic, then the ratio of radii of the spheres in these systems will respectively be :

1. $\left(\frac{1}{2}\right)a:\left(\frac{\sqrt{3}}{2}\right)a:\left(\frac{\sqrt{2}}{2}\right)a$
2. $1a:\sqrt{3}a:\sqrt{2}a$
3. $\left(\frac{1}{2}\right)a:\left(\frac{\sqrt{3}}{4}\right)a:\left(\frac{1}{2\sqrt{2}}\right)a$
4. $\left(\frac{1}{2}\right)a:\sqrt{3}a:\left(\frac{1}{\sqrt{2}}\right)a$

Q.

A solid has a BCC structure. If the distance of the nearest approach between two atoms is 1.73 $\stackrel{\mathrm{o}}{\mathrm{A}}$. What would be the edge length of the cell?

1. 141 pm

2. 200 pm

3. 216 pm

4. 314.20 pm