Relation Between r and a

Q.

What is the Relation Between Edge Length a and Radius of Atom R for BCC Lattice?

Q. Q 29/33 The number of atoms in 100 g of an FCC crystal withdensity d 10 g/cm and cell edge equal to 100 pm, is equal to

Q. An alloy of copper, silver and gold is found have constituting the ccp lattice.If silver atom occupy the edge centers and gold is present at body center, then the alloy has a formula? (a) CuAg3Au (b) Cu4Ag4Au (c) Cu4Ag3Au (d) CuAgA

Q.

Lithium forms body-centered cubic structure. The length of the side of its unit cell is $351\mathrm{pm}$. What will be the Atomic radius of lithium?

1. $152\mathrm{pm}$

2. $175\mathrm{pm}$

3. $240\mathrm{pm}$

4. $300\mathrm{pm}$

Q. 34. The number of moles of sulphur present in mole of H2SO4

Q.

A given metal crystallizes out with a cubic structure having edge length of 361 pm. If there are four metal atoms in one unit cell, what is the radius of one atom?

1. 108 pm

2. 40 pm

3. 127 pm

4. 80 pm

Q.

A binary solid $\left(A^{+}{B}^{-}\right)$ has a rock salt structure. If the edge length is 400 pm and radius of cation is 75 pm, the radius of anion is

1. 100 pm

2. 125 pm

3. 250 pm

4. 325 pm

Q. An element A (Atomic weight = 120) having bcc structure has unit edge length 400 pm. Identify the correct option(s). (Given: $N_A=6\times {10}^{23}$)

1. The density of solid element is $6.25g/c{m}^3$
2. There are $6\times {10}^{22}$ unit cells in 24 g of the solid element
3. The atomic radius is about $1.732\stackrel{\circ }{A}$
4. In 25 g of solid element, the volume occupied by atoms is nearly $2.72c{m}^3$ only

Q. An alloy of copper, silver and gold is found to have copper constituting the ccp lattice. If silver atoms occupy the edge centres and gold is present atbody centre, the alloy has a formula

Q. 12.A cubic solid is made of two different atoms P and Q. Atoms P are present at the corners of the cube and Q are present at the alternate face centers.What is the formula of the compound ?

Q. Do ionic compounds always have hydration enthalpy more than lattice enthalpy?

Q. Copper crystallises in a structure of face centred cubic unit cell. The atomic radius of copper is $1.28A^{\circ }$. What is the edge length of a unit cell of copper?

1. $2.16A^{\circ }$
2. $3.62A^{\circ }$
3. $3.94A^{\circ }$
4. $4.15A^{\circ }$

Q. An element A (Atomic weight = 120) having bcc structure has unit edge length 400 pm. Identify the correct option(s). (Given: $N_A=6\times {10}^{23}$)

1. The density of solid element is $6.25g/c{m}^3$
2. There are $6\times {10}^{22}$ unit cells in 24 g of the solid element
3. The atomic radius is about $1.732\stackrel{\circ }{A}$
4. In 25 g of solid element, the volume occupied by atoms is nearly $2.72c{m}^3$ only

Q. Sodium metal crystallizes as a body centred cubic lattice with the cell edge 4.29 $\stackrel{\circ }{A}$. What is the radius of sodium atom

1. $1.857\times {10}^{-8}$
2. $2.371\times {10}^{-7}$
3. $3.817\times {10}^{-8}$
4. $9.312\times {10}^{-7}$

Q.

A binary solid $\left(A^{+}{B}^{-}\right)$ has a rock salt structure. If the edge length is 400 pm and radius of cation is 75 pm, the radius of anion is

1. 100 pm

2. 125 pm

3. 250 pm

4. 325 pm

Q. An element of density $7gc{m}^{-3}$ occurs in bcc structure with cell edge of $300pm$. Calculate the number of atoms present in $200g$ of the element.

1. $$1.2\times {10}^{24}$$
2. $$1.2\times {10}^{42}$$
3. $$2.1\times {10}^{24}$$
4. $$2.4\times {10}^{42}$$

Q. 2.An alloy consists of Cu at face centre, Au at body centre, Cr at edge centre Andre at corners.If all atoms touching 1tetrad axis of symmetry are removed , then find the new formula of the unit cell.

Q. Copper has face centred cubic (fcc) lattice with interatomic spacing equal to 2.54A . The value of lattice constant for this laticce

Q.

RbCl has NaCl type lattice and its unit cell length is $0.30\stackrel{\circ }{A}$ greater than that for KCl. If $r_{k+}=1.33\stackrel{\circ }{A}$, the ionic radius of $R{b}^{+}$ is

1. $1.48\stackrel{\circ }{A}$

2. $1.63\stackrel{\circ }{A}$

3. $1.03\stackrel{\circ }{A}$

4. $Noneofthese$

Q. Sodium metal crystallizes as a body centred cubic lattice with the cell edge 4.29 $\stackrel{\circ }{A}$. What is the radius of sodium atom

1. $1.857\times {10}^{-8}$
2. $2.371\times {10}^{-7}$
3. $3.817\times {10}^{-8}$
4. $9.312\times {10}^{-7}$

Q.

Calculate r and a relationship from the following figure. All spheres are of equal radius r.

If r = x * a, round off x to 2 decimals and type 100x.

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Q.

Edge length of a cubic unit cell is 400 pm. Its face diagonal would be

1. 600 pm

2. 200 pm

3. 566 pm

4. 692 pm

Q. If atom A is ideally fit in an octahedral void formed by atom B which crystallizes in fcc structure of radius 1.42 Å then what will be the minimum distance between centers of A and B (in Å)? (Use $\sqrt{2}=1.41$)

Q.

What is the relation between the radius of circle 'r' and side of the square 'a' in this figure?

If $x\ast r=a$, type x.

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Q.

Not let's try this in 3-D. Calculate r and a relationship from the following figure.

If $a=x\ast r$, type x.

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Q. CsCl crystallizes in B.C.C lattice. If ‘a’ is its edge length then which of the following expressions is correct?

1. $r_{Cs}+r_{C{l}^{-}}=\frac{\sqrt{3}}{2}a$
2. $r_{C{l}^{-}}+r_{Cs}=\sqrt{3}a$
3. $r_{Cs}+r_{C{l}^{-}}=3a$
4. $r_{Cs}+r_{C{l}^{-}}=\frac{3a}{2}$

Q. calculate number of moles of KMnO_{} which reacts with 2 N, 1500 ml FeC_2O_4

Q. A metal crystallizes with a face-centered cubic lattice. The edge length of the unit cell is 408 pm. The diameter of the metal atom is :

1. 288 pm
2. 408pm
3. 144 pm
4. 204 pm

Q. A metal crystallises in bcc lattice. The percentage fraction of edge length not covered by the atom is:
(Given $\sqrt{3}=1.73$)

1. 10.4 %
2. 13.4 %
3. 12.4 %
4. 11.4 %