Which of the following compound is weakest Lewis acid ?

(1) BF₃

(2) BCl₃

(3) BBr₃

(4) BI₃

The element among the following that does not show inert pair effect is-

The correct order of Lewis acid strength of trihalides of boron is:

1. BCl₃ > BBr₃ > BF₃ > BI₃

2. BF₃ < BBr₃ < BCl₃ < BI₃

3. BF₃ < BCl₃ < BBr₃ < BI₃

4. BF₃ >BCl₃ > BBr₃ > BI₃

The dissolution of $\mathrm{Al}(\mathrm{OH}{)}_3$ in a solution of $\mathrm{NaOH}$ results in the formation of -

1. ${\left[\mathrm{Al}{\left({\mathrm{H}}_2\mathrm{O}\right)}_4{\left(\mathrm{OH}\right)}_2\right]}^{+}$       

2. $\left[\mathrm{Al}{\left({\mathrm{H}}_2\mathrm{O}\right)}_3{\left(\mathrm{OH}\right)}_3\right]$

3. ${\left[\mathrm{Al}{\left({\mathrm{H}}_2\mathrm{O}\right)}_2{\left(\mathrm{OH}\right)}_4\right]}^{-}$     

4. $\left[\mathrm{Al}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6{\left(\mathrm{OH}\right)}_3\right]$

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

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 \(B — O — B\) bonds.

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

4. It is made up of two triangular \(BO_{3}\) units and two tetrahedral \(BO_{4}\) units.

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

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 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 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 ${\mathrm{NH}}_3$

Metal protected by a layer of its own oxide is:

1.  Al

2.  Ag

3.  Au

4.  Cu