Boric acid is polymeric because of:

1. Its acidic nature

2. Presence of hydrogen bonds

3. Its monobasic nature

4. Its geometry

Boric acid on heating at $150°\mathrm{C}$ gives:

1. ${\mathrm{B}}_2{\mathrm{O}}_3$

2. ${\mathrm{H}}_2{\mathrm{B}}_4{\mathrm{O}}_7$

3. ${\mathrm{HBO}}_2$

4. ${\mathrm{H}}_2{\mathrm{BO}}_3$

The product formed in the reaction,

$BC{l}_3+H_{2}O\to$Product is:

(1) $H_{3}B{O}_3+HCl$

(2) $B_2{O}_3+HOCl$

(3) $B_2{H}_6+HCl$

(4) no reaction

The correct statement among the following about H₃BO₃ is:
1. Monobasic and weak Lewis acid

2. Monobasic and weak Bronsted acid

3. Monobasic and strong Lewis acid

4. Tribasic and weak Bronsted acid

On the addition of mineral acid to an aqueous solution of borax, the compound formed is:

1. borodihydride

2. orthoboric acid

3. metaboric acid

4. pyroboric acid

Borax is prepared by treating boric acid with:

(1) $NaN{O}_3$

(2) NaCl

(3) $N{a}_{2}C{O}_3$

(4) $NaHC{O}_3$

The main factor responsible for weak acidic nature of  B-F bonds in $B{F}_3$ is:

(1) large electronegativity of F

(2) three centred two electrons bonds in $B{F}_3$

(3) px-$d\mathrm{\pi }$ back bonding

(4) $p\mathrm{\pi }-\mathrm{p\pi }$ back bonding 

 Which among the following is a gas?

1. $B{F}_3$

2. $BC{l}_3$

3. $BB{r}_3$

4. $B{I}_3$

B-F bond order in $B{F}_3$ is:

(1) 1

(2) 2

(3) 3

(4) 4/3

Aluminium reacts with nitrogen to form:

1. AlN

2. $A{l}_2{N}_3$

3. $A{l}_{2}N$

4. $A{l}_4{N}_6$