JEE CHEMISTRY MCQ: 13 TH GROUP ELEMENTS (P-BLOCK)

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

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

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Correct option: C

\mathbf{A}

is true but

\mathbf{R}

is false.

Option C is correct because orthoboric acid (H3BO3) acts as a Lewis acid, accepting OH- from water, not as a proton donor. Therefore, the reason is false.

More Questions from 13 TH GROUP ELEMENTS (P-BLOCK)

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Duralumin is an alloy of: Assertion (A) : In aqueous solution

{AlCl}_3

forms dimer

{Al}_2 {Cl}_6

.
Reason (R) : The high enthalpy of hydration is sufficient to break the covalent dimer into

\left[M\left({H}_2 {O}\right)_6\right]^{3+}

and

{Cl}^{-}

ions.

{Al}_2\left({SO}_4\right)_3

is used in the following but not Which metal will give blue colour metaborate in borax bead test? Consider the following statements about boric acid.

I. It is a weak monobasic acid

II. It is not a protonic acid

III. It acts as a lewis acid

The correct statement(s) among the following is/are The correct statements from the following are:

(A) The decreasing order of atomic radii of group 13 elements is

{Tl}>{In}>{Ga}>{Al}>{B}

(B) Down the group 13 electronegativity decreases from top to bottom

(C)

{Al}

dissolves in dil.

{HCl}

and liberate

{H}_2

but conc.

{HNO}_3

renders

{Al}

passive by forming a protective oxide layer on the surface

(D) All elements of group 13 exhibits highly stable +1 oxidation state

(E) Hybridisation of

{Al}

\left[{Al}\left({H}_2{O}\right)_6\right]^{3+}

ion is

\mathrm{sp}^3 \mathrm{d}^2

Choose the correct answer from the options given below: