Which of the following compound(s) can react with ${\mathrm{BF}}_3$?

1.  Ethers

2.  ${\mathrm{H}}_2\mathrm{O}$

3.  ${\mathrm{NH}}_3$

4.  All of the above

Which of the following statement is incorrect regarding B-F bond in ${\mathrm{BF}}_3$?

1.  All the three B-F bond lengths are equal and each of them is shorter than the sum of the covalent radii of boron and fluorine

2.  The bond energy of the B-F bond is very high, higher than for any other single bond

3.  The unusual shortness and strength of the B-F bond may be explained by $p\pi -p\pi$ interaction between boron and fluorine atoms

4.  The unusual shortness and strength of the bonds may be explained by a $p\pi -d\pi$ interaction between boron and fluorine atoms

Under hydrolytic conditions, the compounds used for the preparation of the linear polymer and for chain termination, respectively, are

1.  ${\mathrm{CH}}_3{\mathrm{SiCl}}_3 \mathrm{and} \mathrm{Si}{\left({\mathrm{CH}}_3\right)}_4$

2.  ${\left({\mathrm{CH}}_3\right)}_2{\mathrm{SiCl}}_2 \mathrm{and} {\left({\mathrm{CH}}_3\right)}_3\mathrm{SiCl}$

3.  ${\left({\mathrm{CH}}_3\right)}_2{\mathrm{SiCl}}_2 \mathrm{and} {\mathrm{CH}}_3{\mathrm{SiCl}}_3$

4.  ${\mathrm{SiC}}_4 \mathrm{and} {\left({\mathrm{CH}}_3\right)}_3\mathrm{SiCl}$

${\mathrm{Na}}_2{\mathrm{B}}_4{\mathrm{O}}_7\cdot 10{\mathrm{H}}_2\mathrm{O} \underset{∆}{\overset{{740}^{\circ }\mathrm{C}}{\to }} 2{\mathrm{NaBO}}_2+\left(\mathrm{X}\right)+10{\mathrm{H}}_2\mathrm{O}$
$\left(\mathrm{X}\right)+{\mathrm{CaF}}_2+{\mathrm{H}}_2{\mathrm{SO}}_4⟶\mathrm{Y}+{\mathrm{CaSO}}_4+{\mathrm{H}}_2\mathrm{O}$
$\left(\mathrm{Y}\right)+{\mathrm{NaBH}}_4⟶\left(\mathrm{Z}\right)+{\mathrm{NaBF}}_4$

Select the incorrect statement regarding compounds (X), (Y) and (Z).

1.  Compound (X) is ${\mathrm{B}}_2{\mathrm{O}}_3$ and compound (Z) contains two 3C - 2e bonds

2.  Compound (X) is ${\mathrm{B}}_2{\mathrm{O}}_3$ and compound (Y) contains one 3C - 2e bonds 

3.  Compound (Y) is Lewis acid and stable due to $p\pi -p\pi$ back bonding

4.  Compound (Z) reacts with excess of ${\mathrm{NH}}_3$ at high temperature gives inorganic graphite 

The major products obtained in the reaction of oxalic acid with conc. ${\mathrm{H}}_2{\mathrm{SO}}_4$ upon heating are

1.  $\mathrm{CO}, {\mathrm{CO}}_2, {\mathrm{H}}_2\mathrm{O}$

2.  $\mathrm{CO}, {\mathrm{SO}}_2, {\mathrm{H}}_2\mathrm{O}$

3.  ${\mathrm{H}}_2\mathrm{S}, \mathrm{CO}, {\mathrm{H}}_2\mathrm{O}$

4.  $\mathrm{HCOOH}, {\mathrm{H}}_2\mathrm{S}, \mathrm{CO}$

${\mathrm{Al}}_2{\mathrm{O}}_3$ reacts with 

1.  Only water

2.  Only acids

3.  Only alkalis

4.  Both acids and alkalis

All the products formed in the oxidation of ${\mathrm{NaBH}}_4 \mathrm{and} {\mathrm{l}}_2$, are

1.  ${\mathrm{B}}_2{\mathrm{H}}_6 \mathrm{and} \mathrm{Nal} \mathrm{only}$

2.  ${\mathrm{B}}_2{\mathrm{H}}_6, {\mathrm{H}}_2 \mathrm{and} \mathrm{Nal}$

3.  ${\mathrm{Bl}}_3 \mathrm{and} \mathrm{NaH}$

4.  ${\mathrm{NaBl}}_4 \mathrm{and} \mathrm{Hl}$

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

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