p-Block Elements (Group 13 & 14) · Question 21

Which statement is wrong?

1. Beryl is an example of cyclic silicate.
2. Mg2SiO4 is orthosilicate.
3. Basic structural unit in silicates is the SiO4 tetrahedron.
4. Feldspars are not aluminosilicates.

Name the type of the structure of silicate in which one oxygen atom of [SiO4]4- is shared.

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

The tendency of BF3, BCl3 and BBr3 to behave as Lewis acid decreases in the sequence

1. BCl3 > BF3 > BBr3
2. BBr3 > BCl3 > BF3
3. BBr3 > BF3 > BCl3
4. BF3 > BCl3 > BBr3

The stability of +1 oxidation state among Al, Ga, In and Tl increases in the sequence

1. Al < Ga < In < Tl
2. Tl < In < Ga < Al
3. In < Tl < Ga < Al
4. Ga < In < Al < Tl

The straight chain polymer is formed by

1. hydrolysis of CH3SiCl3 followed by condensation polymerisation
2. hydrolysis of (CH3)4Si by addition polymerisation
3. hydrolysis of (CH3)2SiCl2 followed by condensation polymerisation
4. hydrolysis of (CH3)3SiCl followed by condensation polymerisation

Which of the following oxidation states are the most characteristic for lead and tin respectively?

1. +2, +4
2. +4, +4
3. +2, +2
4. +4, +2

Which of the following anions is present in the chain structure of silicates?

1. (Si2O52-)n
2. (SiO32-)n
3. SiO44-
4. Si2O76-

Which one of the following statements about the zeolite is false?

1. They are used as cation exchangers.
2. They have open structure which enables them to take up small molecules.
3. Zeolites are aluminosilicates having three dimensional network.
4. Some of the SiO44- units are replaced by AlO45- and AlO69- ions in zeolites.

Which one of the following compounds is not a protonic acid?

1. B(OH)3
2. PO(OH)3
3. SO(OH)2
4. SO2(OH)2

PbO2 PbO; G298 < 0 SnO2 SnO; G298 > 0 Most probable oxidation state of Pb and Sn will be

1. Pb4+, Sn4+
2. Pb4+, Sn2+
3. Pb2+, Sn2+
4. Pb2+, Sn4+