BCl₃  has higher stability than ${\mathrm{TlCl}}_3$, because -

Boron trifluoride behaves as a Lewis acid because -

1. Boron trifluoride is electron-rich.

2. Boron trifluoride is electron-deficient.

3. Boron trifluoride is highly stable.

4. None of these.

Boric acid is a-

1. Protic acid.

2. Weak monobasic acid.

3. Lewis acid.

4. Both '2' and '3'

The effect of heating Boric acid at 370 K or above is -

1. Orthoboric acid changes to metaboric acid.

2. Metaboric acid changes to boric oxide.

3. Both '1' and '2'

4. Neither '1' nor '2'

The electron-deficient compound among the following is -

1. ${\mathrm{SiCl}}_4$

2. ${\mathrm{BCl}}_3$

3. ${\mathrm{PCl}}_3$

4. $\mathrm{ICl}$

The B–F bond lengths in ${\mathrm{BF}}_3$ (130 pm) and $\mathrm{B}{{\mathrm{F}}_4}^{-}$(143 pm) differ because of:

1. Presence of triple bond character in ${\mathrm{BF}}_3$

2. Resonance in $\mathrm{B}{{\mathrm{F}}_4}^{-}$

3. Presence of a double bond character in ${\mathrm{BF}}_3$

4. Presence of a double bond character in $\mathrm{B}{{\mathrm{F}}_4}^{-}$

Despite the dipole moment in the B–Cl bond, the BCl₃ molecule as a whole has no dipole moment because:

Amphoteric oxides are:

1. Tl₂O₃, SiO₂

2. ${\mathrm{CO}}_2$, ${\mathrm{B}}_2{\mathrm{O}}_3$

3. ${\mathrm{B}}_2{\mathrm{O}}_3$, ${\mathrm{SiO}}_2$

4. Al₂O₃ , PbO₂

An aqueous solution of Borax is-

Boric acid is polymeric due to-

1. Its acidic nature.

2. The presence of hydrogen bonds.

3. Its monobasic nature.

4. Its geometry.