13 th group elements (p-block) practice · Mixed difficulty

The correct Lewis acid order for boron halides is:

The number of electrons present in the valency shell of group 13:

Assertion (A) : Aluminium trimethyl is a dimer having structure like that of ${AlCl}_3$.

Reason (R) : There is three-centre two-electron bonding in ${Al}-{C}-{Al}$ bridge.

Which is used in high temperature thermometry?

The precious stone aquamarine is:

Consider the following reaction

${H_3}B{O_3}\xrightarrow{\Delta }A\xrightarrow[\Delta ]{{{\text{Red}}\,\,{\text{hot}}}}B$

$A$ and $B$ respectively are

Consider the following statement about the following reactions :

$A$ : $2 {H}_2 {O}({l})+2 {~F}_2({~g}) \rightarrow 4 {HF}({g})+{O}_2({~g})$

$B$ : ${BF}_3+{HF} \rightarrow {HBF}_4$

I. Reaction ($A$) is redox reaction whereas reaction $(B)$ is acid-base reaction

II. In reaction ($A$) ${H}_2 {O}$ is oxidising agent.

III. In reaction $({B}), {BF}_3$ is Lewis base.

Choose the correct statement(s) :

The elements having the maximum and minimum melting points among the members of group 13 are respectively-

Amorphous boron on burning in air forms:

${\mathrm{B}_2}{\mathrm{O}_3}$ is:

In the reaction ${\mathrm{B}_2}{\mathrm{O}_3} + \mathrm{C} + \mathrm{C}{\mathrm{l}_2} \to A + \mathrm{CO}.$ The A is

The number of neutrons present in the more abundant isotope of boron is $x.$ Amorphous boron upon heating with air forms a product, in which the oxidation state of boron is $y.$ The value of $x+y$ is

Which of the following is not correct in case of boron nitride?

The relationship between first, second and third ionisation enthalpies of each group-13 element is

Diborane cannot be obtained from

The incorrect statement reading ‘x’ in the reaction is $B{F_3} + LiAl{H_4}\xrightarrow{{\mathrm{Ether}}}\left( x \right) + LiF + Al{F_3}$

${13^{th}}$ group element with least melting point is:

The maximum number of atoms is lying in one plan for $\mathrm{B}_2 \mathrm{H}_6$ is

Standard electrode potential values, $E^{{S}}$ for ${Al}^{3+} / {Al}$ is $-1.66 \mathrm{~V}$ and that of ${Tl}^{3+} / {Tl}$ is $+1.26 \mathrm{~V}$. Which of the following is incorrect regarding the given information?

An alumina-silica clay, called bentonite is dropped from aeroplanes in the slurry form for:

Assertion (A) : In water, orthoboric acid behaves as a weak monobasic acid.

Reason (R) : In water orthoboric acid acts as a proton donor.

Pyrex glass is a mixture of :

Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R:

Assertion A : The stability order of +1 oxidation state of $\mathrm{Ga}$, $\mathrm{In}$ and $\mathrm{Tl}$ is $\mathrm{Ga} < \mathrm{In} < \mathrm{Tl}$.

Reason R : The inert pair effect stabilizes the lower oxidation state down the group.

In the light of the above statements, choose the correct answer from the options given below :

Borax bead test is used to identify the Meta borates of transition metals. It is based on

Colour of the bead in borax bead test is mainly due to the formation of:

Boric acid is an acid because its molecule

In borax bead test which compound is formed?

Anodised aluminium is:

In which of the following compound '3C-2e' bonds are present:

Boric acid is not used: