${\left({\mathrm{si}}_2{\mathrm{O}}_5\right)}_{\mathrm{n}}^{2\mathrm{n}-}$ anion is obtained when :

(a) no oxygen of a ${\mathrm{SiO}}_4^{4-}$ tetrahedron is shared with another ${\mathrm{SiO}}_4^{4-}$ tetrahedron

(b) one oxygen of a ${\mathrm{SiO}}_4^{4-}$ tetrahedron is shared with another ${\mathrm{SiO}}_4^{4-}$ tetrahedron

(c) two oxygen of a ${\mathrm{SiO}}_4^{4-}$ tetrahedron is shared with another ${\mathrm{SiO}}_4^{4-}$ tetrahedron

(d) three oxygen of a ${\mathrm{SiO}}_4^{4-}$ tetrahedron is shared with another ${\mathrm{SiO}}_4^{4-}$ tetrahedron

Amphibole silicate structure has 'x' number of corner shared per tetrahedon. The value of 'x' is :

(a) $2$                            (b) $2\frac{1}{2}$

(c) $3$                             (d) $4$ 

In which of the following silicates, only two corners per tetrahedron are shared?

(i) Pyro silicate                              (ii) Cyclic silicate 

(iii) Double chain silicate                (iv) Single chain silicate 

(v) 3D silicate                                (vi) Sheet silicate

Options are as follows :

(1) (i), (ii), and (v)                             

(2) (iv) and (vi) only

(3) (i) and (vi) only                             

(4) (ii) and (iv) only 

The correct code for stability of oxidation states for given cations is :

(a) ${\mathrm{Pb}}^{2+}>{\mathrm{Pb}}^{4+}, {\mathrm{Bi}}^{3+}>{\mathrm{Bi}}^{5+}$                (b) ${\mathrm{Tl}}^{3+}<{\mathrm{In}}^{3+}, {\mathrm{Sn}}^{2+}>{\mathrm{Sn}}^{4+}$

(c) ${\mathrm{Sn}}^{2+}<{\mathrm{Pb}}^{2+}, {\mathrm{Sn}}^{4+}>{\mathrm{Pb}}^{4+}$               (d) ${\mathrm{Sn}}^{2+}<{\mathrm{Pb}}^{2+}, {\mathrm{Sn}}^{4+}<{\mathrm{Pb}}^{4+}$

1. (a) and (b)                                     
2. (a), (b) and (c)
3. (a) and (c)                                   
4. (b) and (d)

The incorrect statement regarding above reactions is :

${\mathrm{BF}}_3+{\mathrm{LiAlH}}_4\stackrel{\mathrm{Ether}}{\to }\left(\mathrm{X}\right)+\mathrm{LiF}+{\mathrm{AlF}}_3$

(1) Twelve electrons are involed in bonding 

(2) Four, two centre-two electron bonds

(3) Two, three centre-two electron bonds 

(4) X does not react with ${\mathrm{NH}}_3$

The incorrect statement regarding above reactions is :

(a) Al shows amphoteric character

(b) Gas 'P' and 'Q' are different

(d) Both X and Y are water soluble

(d) Gas Q is inflammable

The species among the following that does not exist is-

1. ${\left(\mathrm{Sn}{F}_6\right)}^{2-}$

2. ${\left({\mathrm{GeCl}}_6\right)}^{2-}$

3. ${\left({\mathrm{CCl}}_6\right)}^{2-}$

4. ${\left({\mathrm{SiF}}_6\right)}^{2-}$

$\mathrm{B}(\mathrm{OH}{)}_3+\mathrm{NaOH}\underset{}{\to }{\mathrm{NaBO}}_2+\mathrm{Na}\left[\mathrm{B}{\left(\mathrm{OH}\right)}_4\right]+{\mathrm{H}}_2\mathrm{O}$

How can this reaction is made to proceed in forward direction?

(a) addition of cis1, 2 diol                   (b) addition of borax

(c) addition of trans1, 2 diol                (d) addition of ${\mathrm{Na}}_2{\mathrm{HPO}}_4$

The incorrect statement among the following regarding borax is-

1. It is a useful primary standard for titrating against acids. 

2. One molecule of borax contains 4 $\mathrm{B}—\mathrm{O}—\mathrm{B}$ bonds.

3. Aqueous solution of borax can be used as a buffer.

4. It is made up of two triangular ${\mathrm{BO}}_3$ units and two tetrahedral ${\mathrm{BO}}_4$ units.

Choose the correct squence for the geometry of thr given molecules Borazone, Borazole, ${\mathrm{B}}_3{\mathrm{O}}_6^{3-}, {\mathrm{Fe}}_2{\mathrm{Cl}}_{6,}$ trimer of FCN. ('P' stands for planar and 'NP' stdans for non-planar)

(1) NP, NP, NP, P, P                                 

(2) P, P, NP, NP, P

(3) NP, NP, NP, P, NP                                 

(4) NP, P, P, NP, P