JEE Main - 10th January 2019 Shift 2

Given below are two statements:

Statement I: The decrease in first ionization enthalpy from $\mathrm{B}$ to $\mathrm{Al}$ is much larger than that from $\mathrm{Al}$ to $\mathrm{Ga}$.

Statement II: The d orbitals in $\mathrm{Ga}$ are completely filled.

In the light of the above statements, choose the most appropriate answer from the options given below

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A): In expensive scientific instruments, silica gel is kept in watch-glasses or in semipermeable membrane bags.

Reason (R): Silica gel adsorbs moisture from air via adsorption, thus protects the instrument from water corrosion (rusting) and / or prevents malfunctioning.

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

Bond dissociation energy of $\mathrm{E}-\mathrm{H}$ bond of the "${\mathrm{H}}_2\mathrm{E}$" hydrides of group $16$ elements (given below), follows order.
(A) $\mathrm{O}$
(B) $\mathrm{S}$
(C) $\mathrm{Se}$
(D) $\mathrm{Te}$

Boric acid in solid, whereas ${\mathrm{BF}}_3$ is gas at room temperature because of

The Lewis acid character of boron tri halides follows the order:

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

Assertion A: Amongst $\mathrm{He}, \mathrm{Ne}, \mathrm{Ar}$ and $\mathrm{Kr}$; $1 \mathrm{g}$ of activated charcoal adsorbs more of $\mathrm{Kr}$.

Reason R: The critical volume ${\mathrm{V}}_{\mathrm{c}} ({\mathrm{cm}}^3 {\mathrm{mol}}^{–1})$ and critical pressure ${\mathrm{P}}_{\mathrm{c}}$ (atm) is highest for Krypton but the compressibility factor at critical point ${\mathrm{Z}}_{\mathrm{c}}$ is lowest for Krypton.

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

Given below are two statements:

Statement I: Chlorine can easily combine with oxygen to from oxides: and the product has a tendency to explode.

Statement II: Chemical reactivity of an element can be determined by its reaction with oxygen and halogens.

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

The correct order of bond enthalpy ($\mathrm{kJ} {\mathrm{mol}}^{–1}$) is: