Q 1 :

The correct statements from the following are:                                      [2026]

A. Ionic radii of trivalent cations of group 13 elements decreases down the group.
B. Electronegativity of group 13 elements decreases down the group.
C. Among the group 13 elements, boron has the highest first ionisation enthalpy.
D. The trichloride and triiodide of group 13 elements are covalent in nature.

Choose the correct answer from the options given below:

• A and D only

   

• B and D only

   

• A and C only

   

• C and D only

   

Q 2 :

Consider the following reactions

${\text{Na}}_2{\text{B}}_4{\text{O}}_7\stackrel{\Delta }{\to }2X+Y$

${\text{CuSO}}_4+Y\stackrel{\text{Non-luminous flame}}{\to }Z+{\text{SO}}_3$

$2Z+2X+\text{Carbon}\stackrel{\text{Luminous flame}}{\to }2Q+{\text{Na}}_2{\text{B}}_4{\text{O}}_7+\text{CO}$

The oxidation states of Cu in Z and Q, respectively are:  [2026]

• +2 and +2

   

• +1 and +1

   

• +2 and +1

   

• +1 and +2

   

Q 3 :

Which is not correct in case of Be and Al?

• Both are rendered passive by conc. ${\mathrm{HNO}}_3$

   

• Both give hydroxides which are basic

   

• Carbides of both give methane on hydrolysis

   

• Both give covalent chlorides

   

Q 4 :

Correct order of ${\mathrm{IP}}_1$ is

• $\mathrm{B}>\mathrm{Al}>\mathrm{Ga}>\mathrm{In}>\mathrm{Tl}$

   

• $\mathrm{B}>\mathrm{Tl}>\mathrm{Ga}>\mathrm{Al}>\mathrm{In}$

   

• $\mathrm{B}>\mathrm{Ga}>\mathrm{Al}>\mathrm{Tl}>\mathrm{In}$

   

• $\mathrm{B}>\mathrm{Al}>\mathrm{Ga}>\mathrm{Tl}>\mathrm{In}$

   

Q 5 :

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

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

• Assertion (A) is True, Reason (R) is True; Reason (R) is a Correct explanation for Assertion (A)

   

• Assertion (A) is True, Reason (R) is True; Reason (R) is NOT a Correct explanation for Assertion (A)

   

• Assertion (A) is True, Reason (R) is False

   

• Assertion (A) is False, Reason (R) is True

   

Q 6 :

Maximum number of atoms present in a plane in diborane is X. Maximum number of atoms present in a plane in Borazine is Y. Then, what is the value of $\frac{X+Y}{2}$ ?

(Consider those planes which contain maximum number of atoms)

Q 7 :

The $I.E_1$ among the group 13 member follows as

• $B>Al>Ga<Tl<In$

   

• $B>Ga>Al>Tl>In$

   

• $B>Tl>Ga>Al>In$

   

• $Al>Ga>Tl>B>In$

   

Q 8 :

The correct statements from the following are:

A)  The increasing order of atomic radii of group 13 elements is $B<Al<Ga<In<Tl$.

B)  Al dissolves in dil. HCl and liberate $H_2$ but conc. $HN{O}_3$ renders Al passive by forming a protective oxide layer on the surface.

C)  All elements of group 13 exhibits highly stable +1 oxidation state.

D)  Hybridisation of Al in ${\left[Al{\left(H_{2}O\right)}_6\right]}^{3+}$ ion is $s{p}^3{d}^2$.

Choose the correct answer from the options given below:

• (B) and (D) only

   

• (A) and (C) only

   

• (A), (B) and (C) only

   

• (A) and (B) only

   

Q 9 :

Given below are two statements:

Statement I: Aluminium is more electropositive than thallium as the standard electrode potential value of $E_{{\text{Al}}^{3+}/\text{Al}}^{\circ }$ is negative and $E_{{\text{Tl}}^{3+}/\text{Tl}}^{\circ }$ is positive.

Statement II: The sum of first three ionization enthalpies of boron is very high when compared to that of aluminium. Due to this reason boron forms covalent compounds only and aluminium forms ${\text{Al}}^{3+}$ ion.

In the light of the above statements, choose the correct answer from the options given below:              [2026]

• Both Statement I and Statement II are true

   

• Both Statement I and Statement II are false

   

• Statement I is true but Statement II is false

   

• Statement I is false but Statement II is true