Silicates

Q. A mineral having a formula AB_2, crystallizes in the cubic close packed lattice, with A atoms occupying the lattice points.Hence coordination number of A and B atoms are?

Q.

Carbon tetrachloride has no net dipole moment because of

1. Its planar structure

2. Its regular tetrahedral structure

3. Similar sizes of carbon and chlorine atoms

4. Similar electron affinities of carbon and chlorine

Q. the density of Nickel ( face centred cubic cell ) is 8.94 gram per centimetre cube at 20 degree Celsius what is the diameter of the atom

Q. In a crystalline solids, anions are arranged in fcc packing. Cations occupy half the tetrahedral voids and all the octahedral voids. The ratio of cations and anions in the solid is

Q. 22. A compound AB crystallizes in bcc lattice with unit cell edge length of 380 pm . Calculate 1) the distance between oppositely charged ions in the lattice . 2) Calculate radius of cation A+ if radius of anion B- is 175 pm . ( Assume that cation fits exactly in the cubic void ).

Q.

Silicareacts with hot solution of NaOH forming

1. 

2. 

3. $N{a}_{2}Si{O}_3$
   

4. 

Q. 33.A: Cyclic silicates and chain silicates have the same general molecular formula. R: In cyclic silicates, three corners of each SiO4 tetrahedron are shared while in chain silicates only two are shared with other tetrahedra.

Q. Name of the structure of silicates in which four oxygen atoms of $[Si{O}_4{]}^{4-}$ are shared is

1. Pyrosilicate
2. Sheet silicate
3. Linear chain silicate
4. Three dimensional silicate

Q. Which of the following is used in softening of water?

1. Aluminium borate
2. Aluminium silicate
3. Silicones
4. Chlorosilanes

Q.

Asbestos $\left[CaM{g}_{3}O\right(S{i}_4{O}_{11}\left)\right]$ which is a type of amphibole has a general structure as:

1. 

2. 

3. 

4. 

Q. 77 An element crystallises in bcc lattice.Then calculate the coordination numbers of nearest neighbours and next nearest neighbours of the element.

Q. The most likely geometry for a silicate unit is:

1. square planar
2. square pyramidal
3. octahedral
4. tetrahedral

Q.

Name of the structure of silicates in which three oxygen atoms of $[Si{O}_4{]}^{4-}$ are shared -

1. Pyrosilicate

2. Sheet silicate

3. Linear chain silicate

4. Three dimensional silcate

Q. 26. 27 g of Al will react completely with oxygen equals to a)24 g b)8g C)40g d)10g

Q. 48.How many unit cell are present in a cube shaped ideal crystal of NaCl of mass 1.00 g (1)5.14×10²¹ (2)1.28×10²¹ (3)1.71×10²¹ (4)2.57×10²¹

Q. The basic structural unit of zeolite is:

1. $Si{O}_4^{4-}$
2. $Si{O}_2$
3. $(R_{2}SiO{)}_n$
4. $(Si{O}_3{)}_n^{2n-}$

Q.

Fedlspars and zeolites are examples of:

1. Sheet silicates

2. 3-dimensional silicates

3. Cyclic silicates

4. Pyrosilicates

Q. The overall charge present on the cyclic silicate anion $[S{i}_6{O}_{18}{]}^{n-}$ is:

1. -24
2. -12
3. -18
4. -6

Q.

When zeolite (hydrated sodium aluminium silicate), is treated with hard water the sodium ions are exchanged with

1. H⁺ ions

2. Ca⁺² ions

3. Mg⁺² ions

4. Both Ca²⁺ and Mg⁺²

Q. Which one is the incorrect statement regarding 3D sheet silicates ?

1. Negative charge on silicate is neutralised by positive charged metal ions.
2. 3 corners of the silicates were shared to form 3D network
3. Quartz and Tridymite are 3D sheet silicates
4. Silicate units are links together to form 3D silicates

Q.
The silicate anion given above in a mineral has $K^{+},C{a}^{2+}$ and $A{l}^{3+}$ cations in 2:1:2. Number of moles of $A{l}^{3+}$ ions per 4 moles of mineral is

Q. Find the osmotic pressure of $0.05\text{M}$ solution of urea at ${27}^{\circ }C$
$\text{Molecular formula of urea is}\left(C{H}_4{N}_{2}O\right)$

1. $1.2\text{atm}$
2. $2.5\text{atm}$
3. $0.1\text{atm}$
4. $0.7\text{atm}$

Q. $(Si{O}_3{)}_n^{2n^{-}}$ may be the empirical formula of:

1. Cyclic silicates
2. Pyro silicates
3. Chain silicates
4. both a and c

Q. Aluminosilicates have positive charge.

1. True
2. False

Q. The value of n in the molecular formula $B{e}_{n}A{l}_{2}S{i}_6{O}_{18}$ is

1. 3
2. 6
3. 4
4. 1

Q. Formulae of various silicates are given in left column. Match them with their type.

1. Ortho silicates
2. Pyro silicates
3. Cyclic silicates
4. 2D-sheet silicates

Q. CsBr crystallises in a body centred cubic latticeThe unit cell length is 436.6 pm. Given that the atomicmass of Cs 133 and that of Br 80 amu andAvagadro number being 6.02x 102 mol1, the densityof CsBr isAIPMT (Prelims)-2006(2) 0.425 g/cm3(1) 42.5 g/cm(4) 4.25 g/cm(3) 8.25 g/cm

Q. Name the structure of silicates in which only one oxygen atom of $[Si{O}_4{]}^{-}$ are shared:

1. Three dimensional silicate
2. Linear chain silicate
3. Pyrosilicate
4. Sheet silicate

Q. What are the physical and chemical properties of asbestos. Also give its uses.

Q. What is the 5th and 6th coordination number of compound xy where x are in octahedral voids and y forms fcc lattice