The incorrect statement for orthoboric acid is

1.  It can not be titrated satisfactorily with NaOH, as a sharp endpoint is not obtain

2.  The acidity of its aqueous solution increases upon addition of ethylene glycol

3.  It is a weak electrolyte in water

4.  It has a three-dimensional structure due to hydrogen bonding

The coordination number of Al in aluminates, is-

A mixed oxide compound among the following is -

1.  ${\mathrm{PbO}}_2$

2.  ${\mathrm{SnO}}_2$

3.  ${\mathrm{Pb}}_2{O}_3$

4.  ${\mathrm{Pb}}_3{O}_4$

Select the correct statement(s) regarding the following reaction sequence:

 
   

1.  The compound (A) is ${\left({\mathrm{CH}}_3\right)}_2{\mathrm{SiCl}}_2$

2.  The compound D is SiC

3.  The compound (B) is ${\left({\mathrm{CH}}_3\right)}_2\mathrm{Si}{\left(\mathrm{OH}\right)}_2$

4.  All of the above

The number of double bonds at alternate position in ${\mathrm{C}}_{60}$ molecule are

1.  20

2.  25

3.  30

4.  36

Incorrect statement among the following is

1.  ${\mathrm{B}}_{\mathrm{n}}{\mathrm{H}}_{\mathrm{n}+6}$ are known as arachnoboranes

2.  Indium hydride is a polymeric solid

3.  ${\mathrm{AlH}}_3$ is a monomeric planar molecule

4.  Nido-boranes have the general formula ${\mathrm{B}}_{\mathrm{n}}{\mathrm{H}}_{\mathrm{n}+6}$

A species among the following that decomposes easily is: -

A strong oxidizing agent among the following is -

1.  ${\mathrm{Tl}}^{3+}$

2.  ${\mathrm{Ga}}^{3+}$

3.  ${\ln }^{3+}$

4.  ${\mathrm{Al}}^{3+}$

From the following, the compound(s) that react(s) with \(\mathrm{BF}_3\) is/are -

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