The most characteristic oxidation state for lead and tin is, respectively,:

1. +4, +2

2. +2, +4

3. +4, +4

4. +2, +2

An anion present in the chain structure silicate is -

1. ${\mathrm{Si}}_2{\mathrm{O}}_7^{6-}$

2. ${\left({\mathrm{Si}}_2{\mathrm{O}}_5^{2-}\right)}_{\mathrm{n}}$

3. ${\left({\mathrm{SiO}}_3^{2-}\right)}_{\mathrm{n}}$

4. ${\mathrm{SiO}}_4^{4-}$

${}_{}$
\(\mathrm{Al}_2 \mathrm{O}_3\) reacts with-

In the structure of borax, the numbers of boron atoms and B-O-B units, respectively, are

1.  4 and 5

2.  4 and 3

3.  5 and 4

4.  5 and 3

Hydrolysis of ${\mathrm{BCl}}_3$ gives X which on treatment with sodium carbonate produces Y. X and Y, respectively, are 

1.  ${\mathrm{H}}_3{\mathrm{BO}}_3 \mathrm{and} {\mathrm{NaBO}}_2$

2.  ${\mathrm{H}}_3{\mathrm{BO}}_3 \mathrm{and} {\mathrm{Na}}_2{B}_4{O}_7$

3.  ${\mathrm{B}}_2{\mathrm{O}}_3 \mathrm{and} {\mathrm{NaBO}}_2$

4.  $B_2{O}_3 \mathrm{and} {\mathrm{Na}}_2{B}_4{O}_7$

The element that combines with oxygen to give an amphoteric oxide is:

1.  N

2.  P

3.  Al

4.  Na

When a mixture of diborane and ammonia is heated, the final product is

1.  ${\mathrm{BH}}_3$

2.  ${\mathrm{NH}}_4{\mathrm{BH}}_4$

3.  ${\mathrm{NH}}_2{\mathrm{NH}}_2$

4.  ${\mathrm{B}}_3{\mathrm{N}}_3{\mathrm{H}}_6$

The bond energy of B-F bond in ${\mathrm{BF}}_3$ is 646 kJ ${\mathrm{mol}}^{-1}$, while that of N-F bond in ${\mathrm{NF}}_3$ is 280 kJ ${\mathrm{mol}}^{-1}$. This is because

1.  N is more electronegative than B

2.  The atomic mass of N is higher than that of B

3.  The B-F bond gets a partial double bond character due to p-p overlap

4.  N has a lone pair of electrons while B does not have

The hybridization of boron in the stable borane having the lowest molecular weight is

1.  $s{p}^2$

2.  $s{p}^3$

3.  sp

4.  $s{p}^3$d

Identify the cyclic silicates ion given in the figure below

1.  ${\left[S{i}_4{O}_{25}\right]}^{24-}$

2.  ${\left[S{i}_6{O}_{18}\right]}^{12-}$

3.  ${\left[S{i}_4{O}_{12}\right]}^{12-}$

4.  ${\left[S{i}_6{O}_{24}\right]}^{12-}$