Chapter 11

The reaction of \(\mathrm{H}_{3} \mathrm{~N}_{3} \mathrm{~B}_{3} \mathrm{Cl}_{3}(\mathrm{~A})\) with \(\mathrm{LiBH}_{4}\) in tetrahydrofuran gives inorganic benzene (B). Further, the reaction of (A) with (C) leads to \(\mathrm{H}_{3} \mathrm{~N}_{3} \mathrm{~B}_{3}(\mathrm{Me})_{3}\). Compounds (B) and (C) respectively, are: [Main Jan. 09, 2020 (II)] (a) Borazine and \(\mathrm{MeBr}\) (b) Diborane and \(\mathrm{MeMgBr}\) (c) Boron nitride and MeBr (d) Borazine and \(\mathrm{MeMgBr}\)

The correct statement among the following is : [Main April 12, 2019 (I)] (a) \(\left(\mathrm{SiH}_{3}\right)_{3} \mathrm{~N}\) is planar and less basic than \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{~N}\). (b) \(\left(\mathrm{SiH}_{3}\right)_{3} \mathrm{~N}\) is pyramidal and more basic than \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{~N}\). (c) \(\left(\mathrm{SiH}_{3}\right)_{3} \mathrm{~N}\) is pyramidal and less basic than \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{~N}\). (d) \(\left(\mathrm{SiH}_{3}\right)_{3} \mathrm{~N}\) is planar and more basic than \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{~N}\).

\(\mathrm{C}_{60}\), an allotrope of carbon cantains: (a) 12 hexagons and 20 pentagons. (b) 18 hexagons and 14 pentagons. (c) 16 hexagons and 16 pentagons. (d) 20 hexagons and 12 pentagons.

The \(\mathrm{C}-\mathrm{C}\) bond length is maximum in : (a) graphite (b) \(\mathrm{C}_{70}\) (c) \(\mathrm{C}_{60}\) (d) diamond

Diborane \(\left(\mathrm{B}_{2} \mathrm{H}_{6}\right)\) reacts independently with \(\mathrm{O}_{2}\) and \(\mathrm{H}_{2} \mathrm{O}\) to produce, respectively; [Main April 8, 2019 (I)] (a) \(\mathrm{B}_{2} \mathrm{O}_{3}\) and \(\mathrm{H}_{3} \mathrm{BO}_{3}\) (b) \(\mathrm{B}_{2} \mathrm{O}_{3}\) and \(\left[\mathrm{BH}_{4}\right]^{-}\) (c) \(\mathrm{H}_{3} \mathrm{BO}_{3}\) and \(\mathrm{B}_{2} \mathrm{O}_{3}\) (d) \(\mathrm{HBO}_{2}\) and \(\mathrm{H}_{3} \mathrm{BO}_{3}\)

The correct order of catenation is : (a) \(\mathrm{C}>\mathrm{Sn}>\mathrm{Si} \approx \mathrm{Ge}\) (b) \(\mathrm{C}>\mathrm{Si}>\mathrm{Ge} \approx \mathrm{Sn}\) (c) \(\mathrm{Si}>\mathrm{Sn}>\mathrm{C}>\mathrm{Ge}\) (d) \(\mathrm{Ge}>\mathrm{Sn}>\mathrm{Si}>\mathrm{C}\)

The hydride that is NOT electron deficient is (a) \(\mathrm{SiH}_{4}\) (b) \(\mathrm{B}_{2} \mathrm{H}_{6}\) (c) \(\mathrm{GaH}_{3}\) (4) \(\mathrm{AlH}_{3}\)

The element that does NOT show catenation is : [Main Jan. 12, 2019 (II)] (a) Ge (b) Si (c) \(\mathrm{Sn}\) (d) \(\mathrm{Pb}\)

The electronegativity of aluminium is similar to: [Main Jan. 10, 2019 (I)] (a) Carbon (b) Beryllium (c) Boron (d) Lithium

The chloride that CANNOT get hydrolysed is (a) \(\mathrm{PbCl}_{4}\) (b) \(\mathrm{CCl}_{4}\) (c) \(\mathrm{SnCl}_{4}\) (d) \(\mathrm{SiCl}_{4}\)

When metal ' \(\mathrm{M}\) ' is treated with \(\mathrm{NaOH}\), a white gelatinous precipitate \(' \mathrm{X}^{\prime}\) is obtained, which is soluble in excess of \(\mathrm{NaOH}\). Compound ' \(\mathrm{X}^{\prime}\) when heated strongly gives an oxide which is used in chromatography as an adsorbent. The metal ' \(\mathrm{M}\) ' is : \([\) Main \(\mathbf{2 0 1 8}]\) (a) \(\mathrm{Zn}\) (b) \(\mathrm{Ca}\) (c) \(\mathrm{Al}\) (d) \(\mathrm{Fe}\)

Which of the following are Lewis acids? (a) \(\mathrm{PH}_{3}\) and \(\mathrm{BCl}_{3}\) (b) \(\mathrm{AlCl}_{3}\) and \(\mathrm{SiCl}_{4}\) (c) \(\mathrm{PH}_{3}\) and \(\mathrm{SiCl}_{4}\) (d) \(\mathrm{BCl}_{3}\) and \(\mathrm{AlCl}_{3}\)

A group 13 element ' \(X\) ' reacts with chlorine gas to produce a compound \(\mathrm{XCl}_{3} . \mathrm{XCl}_{3}\) is electron deficient and easily reacts with \(\mathrm{NH}_{3}\) to form \(\mathrm{Cl}_{3} \mathrm{X} \leftarrow \mathrm{NH}_{3}\) adduct, however, \(\mathrm{XCl}_{3}\) does not dimerize. \(\mathrm{X}\) is: [Main Online April 16, 2018] (a) B (b) \(\mathrm{Al}\) (c) In (d) \(\mathrm{Ga}\)

The gas evolved on heating \(\mathrm{CaF}_{2}\) and \(\mathrm{SiO}_{2}\) with concentrated \(\mathrm{H}_{2} \mathrm{SO}_{4}\), on hydrolysis gives a white gelatinous precipitate. The precipitate is: [Main Online April 9, 2014] (a) hydrofluosilicic acid (b) silica gel (c) silicic acid (d) calciumfluorosilicate

Identify the reaction which does not liberate hydrogen : [Main Online April 10, 2016] (a) Reaction of lithium hydride with \(\mathrm{B}_{2} \mathrm{H}_{6}\). (b) Electrolysis of acidified water using Pt electrodes (c) Reaction of zinc with aqueous alkali (d) Allowing a solution of sodium in liquid ammonia to stand

Name of the structure of silicates in which three oxygen atoms of \(\left[\mathrm{SiO}_{4}\right]^{4-}\) are shared. [2005S] (a) Pyrosilicate (b) Sheet silicate (c) Linear chain silicate (d) Three dimensional silicate

\((\mathrm{Me})_{2} \mathrm{SiCl}_{2}\) on hydrolysis will produce (a) \((\text { Me })_{2} \mathrm{Si}(\mathrm{OH})_{2}\) (b) \((\mathrm{Me})_{2} \mathrm{Si}=\mathrm{O}\) (c) \(-\left[-\mathrm{O}-(\mathrm{Me})_{2} \mathrm{Si}-\mathrm{O}-\right]_{\mathrm{n}}-\) (d) \(\mathrm{Me}_{2} \mathrm{SiCl}(\mathrm{OH})\)

Which one of the following oxides is neutral? (a) \(\mathrm{CO}\) (b) \(\mathrm{SnO}_{2}\) (c) \(\mathrm{ZnO}\) (d) \(\mathrm{SiO}_{2}\)

\(\mathrm{H}_{3} \mathrm{BO}_{3}\) is: (a) Monobasic and weak Lewis acid (b) Monobasic and weak Bronsted acid (c) Monobasic and strong Lewis acid (d) Tribasic and weak Bronsted acid

Which of the following halides is least stable and has doubtful existence? [1996-1 Mark] (a) \(\mathrm{CI}_{4}\) (b) \(\mathrm{GeI}_{4}\) (c) \(\mathrm{SnI}_{4}\) (d) \(\mathrm{PbI}_{4}\)

Which of the following statements about anhydrous aluminium chloride is correct? [1981-1 Mark] (a) it exists as \(\mathrm{AlCl}_{3}\) molecules (b) it is not easily hydrolysed (c) it sublimes at \(100^{\circ} \mathrm{C}\) under vacuum (d) it is a strong Lewis base

Moderate electrical conductivity is shown by (a) silica (b) graphite (c) diamond (d) carborundum

Lead pencil contains (a) \(\mathrm{Pb}\) (b) \(\mathrm{FeS}\) (c) Graphite (d) \(\mathrm{PbS}\)

The coordination number of \(\mathrm{Al}\) in the crystalline state of \(\mathrm{AlCl}_{3}\) is

A liquid which is permanently supercooled is frequently called a

Among the following, the correct statement(s) is (are) [Adv. 2017] (a) \(\mathrm{Al}\left(\mathrm{CH}_{3}\right)_{3}\) has the three-centre two- electron bonds in its dimeric structure (b) \(\mathrm{BH}_{3}\) has the three-centre two-electron bonds in its dimeric structure (c) \(\mathrm{AlCl}_{3}\) has the three-centre two-electron bonds in its dimeric structure (d) The Lewis acidity of \(\mathrm{BCl}_{3}\) is greater than that of \(\mathrm{AlCl}_{3}\)

One recently discovered allotrope of carbon \(\left(e . g ., \mathrm{C}_{60}\right)\) is commonly known as..........

The crystalline form of borax has (a) tetranuclear \(\left[\mathrm{B}_{4} \mathrm{O}_{5}(\mathrm{OH})_{4}\right]^{2-}\) unit (b) all boron atoms in the same plane (c) equal number of \(s p^{2}\) and \(s p^{3}\) hybridized boron atoms (d) one terminal hydroxide per boron atom

The correct statement(s) for orthoboric acid is/are [Adv. 2014] (a) It behaves as a weak acid in water due to self ionization. (b) Acidity of its aqueous solution increases upon addition of ethylene glycol (c) It has a three dimensional structure due to hydrogen bonding (d) It is a weak electrolyte in water

Match the following : Column I \(\quad\) Column II (A) \(\mathrm{Bi}^{3+} \rightarrow(\mathrm{BiO})^{+}\) (p) Heat (B) \(\left[\mathrm{AlO}_{2}\right]^{-} \rightarrow \mathrm{Al}(\mathrm{OH})_{3}\) (q) Hydrolysis (C) \(\left[\mathrm{SiO}_{4}\right]^{4-} \rightarrow\left[\mathrm{Si}_{2} \mathrm{O}_{7}\right]^{6-}\) (r) Acidification (D) \(\left[\mathrm{B}_{4} \mathrm{O}_{7}\right]^{2-} \rightarrow\left[\mathrm{B}(\mathrm{OH})_{3}\right]\) (s) Dilution by water

Statement-1: Boron always forms covalent bond. because Statement-2 : The small size of \(\mathrm{B}^{3+}\) favours formation of covalent bond.

Statement-1 : In water, orthoboric acid behaves as a weak monobasic acid. because Statement-2 : In water, orthoboric acid acts as a proton donor.

\(\mathrm{AlF}_{3}\) is insoluble in anhydrous HF but it becomes soluble in presence of little amount of KF. Addition of boron trifluoride to the resulting solution causes reprecipitation of \(\mathrm{AlF}_{3}\). Explain with balanced chemical equations.

How is boron obtained from borax? Give chemical equations with reaction conditions. Write the structure of \(\mathrm{B}_{2} \mathrm{H}_{6}\) and its reaction with \(\mathrm{HCl}\).

Compound \((X)\) on reduction with \(\operatorname{LiAlH}_{4}\) gives a hydride \((Y)\) containing \(21.72 \%\) hydrogen along with other products. The compound \((Y)\) reacts with air explosively resulting in boron trioxide. Identify \((X)\) and \((Y)\). Give balanced reactions involved in the formation of \((Y)\) and its reaction with air. Draw the structure of \((Y)\).

Choose the correct statement(s) among the following. (a) \(\mathrm{SnCl}_{2} \cdot 2 \mathrm{H}_{2} \mathrm{O}\) is a reducing agent. (b) \(\mathrm{SnO}_{2}\) reacts with \(\mathrm{KOH}\) to form \(\mathrm{K}_{2}\left[\mathrm{Sn}(\mathrm{OH})_{6}\right]\). (c) A solution of \(\mathrm{PbCl}_{2}\) in \(\mathrm{HCl}\) contains \(\mathrm{Pb}^{2+}\) and \(\mathrm{Cl}^{-}\)ions. (d) The reaction of \(\mathrm{Pb}_{3} \mathrm{O}_{4}\) with hot dilute nitric acid to give \(\mathrm{PbO}_{2}\) is a redox reaction.

State with balanced equations what happens when : (i) Aluminium sulphide gives a foul odour when it becomes damp. Write a balanced chemical equation for the reaction. [1997 - 2 Marks] (ii) Reaction of aluminium with aqueous sodium hydroxide.

Give reason of the following : The hydroxides of aluminium and iron are insoluble in water. However, \(\mathrm{NaOH}\) is used to separate one from the other.

With respect to graphite and diamond, which of the statement(s) given below is (are) correct? \([2012]\) (a) Graphite is harder than diamond. (b) Graphite has higher electrical conductivity than diamond. (c) Graphite has higher thermal conductivity than diamond. (d) Graphite has higher C-C bond order than diamond.

Complete the following equations (no balancing is needed) (i) \(\mathrm{HCO}_{3}^{-}+\mathrm{Al}^{3+} \rightarrow \mathrm{Al}(\mathrm{OH})_{3}+\ldots\) [1981-1 Mark] (ii) \(\mathrm{AlBr}_{3}+\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}+\mathrm{H}_{3} \mathrm{PO}_{4}\) \(\rightarrow \mathrm{K}_{3} \mathrm{PO}_{4}+\mathrm{AlPO}_{4}+\mathrm{H}_{2} \mathrm{O}+\ldots+\ldots\)

The material used in the solar cells contains (a) \(\mathrm{Cs}\) (b) Si (c) \(\mathrm{Sn}\) (d) Ti

Match the items in Column I with its main use listed in Column II: [Main Online April 9, 2016] Column I \(\quad\) Column II (A) Silica gel (i) Transistor (B) Silicon (ii) Ionexchanger (C) Silicone (iii) Drying agent (D) Silicate (iv) Sealant (a) (A)-(iii), (B)-(i), (C)-(iv), (D)-(ii) (b) (A)-(iv), (B)-(i), (C)-(ii), (D)-(iii) (c) (A)-(ii), (B)-(i), (C)-(iv), (D)-(iii) (d) (A)-(ii), (B)-(iv), (C)-(i), (D)-(iii)

Each entry in column \(\mathbf{X}\) is in some way related to the entries in column \(\mathbf{Y}\) and \(\mathbf{Z}\). Match the appropriate entries: [Multiple Concepts, \(1989-5 \times 1=5\) Marks] \(\mathbf{X} \quad \mathbf{Y}\) \(\mathbf{Z}\) A . Mica (a) Graphite crystallite (i) Abrasive B. Superphosphate (b) Cubic (ii) Insulator C. Carbon fibres (c) Layer structure (iii) Fertilizer D. Rock salt (d) Diamond structure (iv) Reinforced plastics E. Carborundum (e) Bone ash (v) Preservative

Assertion : Among the carbon allotropes, diamond is an insulator, whereas, graphite is a good conductor of electricity. Reason : Hybridization of carbon in diamond and graphite are \(s p^{3}\) and \(s p^{2}\), respectively. [Main Online April 10, 2016] (a) Both assertion and reason are correct, but the reason is not the correct explanation for the assertion (b) Both assertion and reason are correct, and the reason is the correct explanation for the assertion (c) Both assertion and reason are incorrect (d) Assertion is incorrect statement, but the reason is correct. This question contains STATEMENT-1 (Assertion/ Statement ) and STATEMENT-2 (Reason/Explanation) and has 4 choices (a), (b), (c) and (d) out of which ONLY ONE is correct. (a) Statement-1 is True, Statement-2 isTrue; Statement-2 is a correct explanation for Statement-1 (b) Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1 (c) Statement-1 is True, Statement- 2 is False (d) Statement-1 is False, Statement- 2 is True.

Statement-1 : \(\mathrm{Pb}^{+4}\) compounds are stronger oxidising agents than \(\mathrm{Sn}^{4+}\) compounds [2008] Statement-2 : The higher oxidation states for the group 14 elements are more stable for the heavier members of the group due to 'inert pair effect'.

Statement-1 : Between \(\mathrm{SiCl}_{4}\) and \(\mathrm{CCl}_{4}\), only \(\mathrm{SiCl}_{4}\) reacts with water. Statement- \(\mathbf{2}: \mathrm{SiCl}_{4}\) is ionic and \(\mathrm{CCl}_{4}\) is covalent.

Starting from \(\mathrm{SiCl}_{4}\), prepare the following in steps not exceeding the number given in parentheses (give reactions only): (i) Silicon (1) (ii) Linear silicone containing methyl groups only (4) (iii) \(\mathrm{Na}_{2} \mathrm{SiO}_{3}(3)\)

Draw the structure of a cyclic silicate, \(\left(\mathrm{Si}_{3} \mathrm{O}_{9}\right)^{6-}\) with proper labelling.

State with balanced equations, what happens when : (i) Tin is treated with moderately concentrated nitric acid. (ii) Aluminium is reacted with hot concentrated caustic soda solution