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

1. +4, +2                     

2. +2, +4

3. +4, +4                     

4. +2, +2

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

(a) ${\mathrm{Si}}_2{\mathrm{O}}_7^{6-}$                 (b) $({\mathrm{Si}}_2{\mathrm{O}}_5^{2-}{)}_{\mathrm{n}}$

(c) $({\mathrm{Si}}_2{\mathrm{O}}_6^{4-}{)}_{\mathrm{n}}$               (d) ${\mathrm{SiO}}_4^{4-}$

Borax is converted into crystalline boron by the following steps:

          $\mathrm{Borax}\stackrel{\mathrm{X}}{\to }{\mathrm{H}}_3{\mathrm{BO}}_3\stackrel{∆}{\to }{\mathrm{B}}_2{\mathrm{O}}_3\underset{∆}{\overset{\mathrm{Y}}{\to }}\mathrm{B}$

X and Y are respectively :

1. HCl, Mg                                 
2. HCl, C
3. C, Al 
4. HCl, Al

The dissolution of $\mathrm{Al}(\mathrm{OH}{)}_3$ in a solution of $\mathrm{NaOH}$ results in the formation of -

1. ${\left[\mathrm{Al}{\left({\mathrm{H}}_2\mathrm{O}\right)}_4{\left(\mathrm{OH}\right)}_2\right]}^{+}$       

2. $\left[\mathrm{Al}{\left({\mathrm{H}}_2\mathrm{O}\right)}_3{\left(\mathrm{OH}\right)}_3\right]$

3. ${\left[\mathrm{Al}{\left({\mathrm{H}}_2\mathrm{O}\right)}_2{\left(\mathrm{OH}\right)}_4\right]}^{-}$     

4. $\left[\mathrm{Al}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6{\left(\mathrm{OH}\right)}_3\right]$

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

shared?

1. Sheet silicate

2. Pyrosilicate

3. three dimensional silicate

4. Linear chain silicate

Which of the following statements regarding borax is incorrect?

1. Borax is used as a primary standard in acid–base titrations.

2. The tetraborate ion present in borax contains four B–O–B bridges.

3.  An aqueous borax solution can act as a buffer.

4. The tetraborate ion consists of two trigonal planar BO₃ units and two tetrahedral BO₄ units.

It is because inability of ns² electrons of the valence shell to participate in bonding that

1. Sn²⁺ is reducing while Pb⁴⁺ is oxidising agent

2. Sn²⁺ is oxidising while Pb⁴⁺ is reducing agent

3. Sn²⁺ and Pb²⁺ are both oxidising and reducing agent

4. Sn⁴⁺ is reducing while Pb⁴⁺ is oxidising agent

How can the following reaction be made to proceed in the forward direction?

1. Addition of cis-1,2 diol
2. Addition of borax
3. Addition of trans-1,2 diol
4. Addition of Na₂HPO₄

Which of the following cation can not give borax bead test?

(a) ${\mathrm{Cr}}^{3+}$                          (b) ${\mathrm{Co}}^{2+}$

(c) ${\mathrm{Ag}}^{+}$                           (d) ${\mathrm{Mn}}^{2+}$

Find the species that does not exist among the following.
1. [SnF₆]²⁻
2. [GeCl₆]²⁻
3. [CCl₆]²⁻
4. [SiF₆]²⁻