Free NEET Chemistry multiple-choice questions on Boron Family (Group 13). Attempt each question and reveal the answer with a full explanation.
Which of the following elements does not show the 'inert pair effect'? Boron Thallium Lead Bismuth In the extraction of Aluminium by the Hall-Heroult process, the role of fluorspar ( CaF 2 ) and cryolite ( Na 3AlF 6 ) is to: Lower the melting point and increase the electrical conductivity of the electrolyte Act as a catalyst for the oxidation of Carbon Decrease the rate of reaction to prevent explosion Increase the purity of the Aluminium obtained When AlCl 3 is dissolved in acidified aqueous solution, it forms a complex ion with the formula: [Al(H 2O) 6] 3+ [Al(OH) 4] - [AlCl 6] 3- [Al(H 2O) 4Cl 2] + The bond angle F-B-F in BF 3 is: 120 109.5 107 90 Which of the following elements in Group 13 has the lowest melting point, allowing it to remain in a liquid state over a very wide temperature range? Gallium Boron Indium Thallium When Aluminum reacts with aqueous Sodium hydroxide ( NaOH ), the products formed are: Sodium meta-aluminate and Hydrogen gas Sodium aluminate and Oxygen gas Aluminum hydroxide and Sodium hydride Sodium oxide and Aluminum hydride Boron sesquioxide ( B 2O 3 ) is classified as a/an oxide. Acidic Basic Amphoteric Neutral Which of the following oxidation states are the most characteristic for lead and tin respectively? +2, +4 +4, +4 +2, +2 +4, +2 Which of the following oxides is not expected to react with sodium hydroxide ? BeO B 2O 3 CaO SiO 2 The stability of +1 oxidation state increases in the sequence : Ga < In < Al < Tl Al < Ga < In < Tl Tl < In < Ga < Al In < Tl < Ga < Al Which of the following structure is similar to graphite? BN B B4C B2H6 Which of the following is known as 'Inorganic Benzene'? B 3N 3H 6 B 3O 3H 6 B 2H 6 C 6H 6 Which one of the following elements is unable to form MF6 3- ion? B Al Ga In Which of the following is an amphoteric hydroxide? Be(OH)2 Sr(OH)2 Ca(OH)2 Mg(OH)2 Which of the following is not correct about carbon monoxide ? It reduces oxygen carrying ability of blood. The carboxyhaemoglobin (haemoglobin bound to CO) is less stable than oxyhaemoglobin. It is produced due to incomplete combustion. It forms carboxyhaemoglobin Which of the following statement is not correct about diborane? The four terminal B-H bonds are two centre two electron bonds. The four terminal Hydrogen atoms and the two Boron atoms lie in one plane. Both the Boron atoms are sp 2 hybridised. There are two 3-centre-2-electron bonds. Choose the correct statement: Diamond is covalent and graphite is ionic. Diamond is sp 3 hybridised and graphite is sp 2 hybridized. Both diamond and graphite are used as dry lubricants. Diamond and graphite have two dimensional network. Match List-I with List-II. array ll List-I & List-II A. Coke & I. Carbon atoms are sp 3 hybridised B. Diamond & II. Used as a dry lubricant C. Fullerene & III. Used as a reducing agent D. Graphite & IV. Cage like molecules array Choose the correct answer from the options given below : A-II, B-IV, C-I, D-III A-IV, B-I, C-II, D-III A-III, B-I, C-IV, D-II A-III, B-IV, C-I, D-II The compound which gives a 'bead test' with metal salts is: Na 2B 4O 7 10H 2O H 3BO 3 B 2O 3 NaBO 2 The structure of Al 2Cl 6 contains: Four terminal Al-Cl bonds and two bridge Al-Cl bonds Three terminal Al-Cl bonds and three bridge Al-Cl bonds Two terminal Al-Cl bonds and four bridge Al-Cl bonds Six terminal Al-Cl bonds The mixture used for the detection of Borate radical in 'Ethyl borate test' consists of Borate salt, concentrated H 2SO 4 , and: Ethanol Methanol Chloroform Acetone Which of the following statements about Boric acid ( H 3BO 3 ) is correct? It has a layered structure joined by hydrogen bonds It is a strong tribasic acid It is a protic acid It is obtained by the hydrolysis of B 2H 6 only The zeolite used to convert alcohols directly into gasoline is: ZSM-5 Zeolite A Zeolite L Mordenite Lead(IV) compounds ( Pb 4+ ) act as strong oxidising agents because: Pb 2+ is more stable than Pb 4+ due to the inert pair effect Pb 4+ is more stable than Pb 2+ Lead has a high electronegativity Lead is a transition metal The correct order of atomic radii for Group 13 elements is: B < Ga < Al < In < Tl B < Al < Ga < In < Tl B < Al < In < Ga < Tl B < Ga < Al < Tl < In Which statement regarding Borazole ( B 3N 3H 6 ) is correct? It is isoelectronic with Benzene It contains no p -p bonds It is more stable than Benzene It is a non-polar molecule Diborane is prepared in the laboratory by the reaction of: NaBH 4 and I 2 BCl 3 and H 2 BF 3 and LiAlH 4 B 2O 3 and Mg The B-F bond length in BF 3 is 130 pm, while in BF 4 - , it is 143 pm. The longer bond length in BF 4 - is due to: Absence of p -p back-bonding in BF 4 - Presence of p -p back-bonding in BF 4 - Change in hybridization of B from sp 3 to sp 2 Increase in electronegativity of Boron Orthoboric acid ( H 3BO 3 ) is a monobasic acid in aqueous solution because: It accepts an OH - from a water molecule It loses a proton ( H + ) from its own structure It contains only one replaceable Hydrogen atom It reacts with NaOH to form a salt and water Aluminum chloride ( AlCl 3 ) exists as a dimer ( Al 2Cl 6 ) in the vapor phase. The dimerization is achieved through: Coordinate bonds from Chlorine to Aluminum Hydrogen bonding p - Ï€ back bonding Ionic interactions Considering the stability of oxidation states, which of the following statements is true for Group 13 elements? In 3+ is more stable than In + , but Tl + is more stable than Tl 3+ In + is more stable than In 3+ , and Tl + is more stable than Tl 3+ Al + is more stable than Al 3+ Tl 3+ is the most stable state for Thallium The structure of orthoboric acid ( H 3BO 3 ) is characterized by: Planar BO 3 3- units linked by hydrogen bonds A three-dimensional network of BO 4 tetrahedra Linear chains of B-O bonds Discrete pyramidal molecules Boron nitride ( BN ) is often called 'Inorganic Graphite' because it: Has a layered structure similar to graphite Has the same electronic configuration as carbon Conducts electricity as well as graphite Is a dark black solid Which of the following is the most stable oxidation state for Thallium ( Tl )? +1 +3 +2 +4 Which of the following is the most powerful oxidising agent among the given species? Tl 3+ Al 3+ Ga 3+ In 3+ Which of the following Boron compounds is used as a shielding material in nuclear reactors due to its high capacity to absorb neutrons? Boron Carbide ( B 4C ) Borax ( Na 2B 4O 7 10H 2O ) Boric Acid ( H 3BO 3 ) Diborane ( B 2H 6 ) The enthalpy of combustion of diborane ( B 2H 6 ) is extremely high, approximately -2035 kJ/mol . This property makes it a potential candidate for which of the following applications? Rocket fuel Gaseous insulator Preservative for food Refrigerant in cryogenics Indium ( In ) shows both +1 and +3 oxidation states. Which of the following is true regarding the stability of these states compared to Thallium ( Tl )? In 3+ is more stable than Tl 3+ In + is more stable than Tl + In + and Tl + are equally stable In 3+ is less stable than In + The reaction of Boron with Nitrogen at very high temperatures results in the formation of a white, slippery solid with a layer structure similar to graphite. This compound is: Boron Nitride ( BN ) Borazole Boron trioxide Diborane In diborane ( B 2H 6 ), the number of 3-center-2-electron bonds and 2-center-2-electron bonds are respectively: 2 and 4 4 and 2 2 and 2 2 and 6 Orthoboric acid ( H 3BO 3 ) is a Lewis acid because: It accepts OH - from water releasing a proton It gives H + ions on its own It contains replaceable H + ions It reacts with bases The tendency to form monovalent compounds among the Group 13 elements is correctly exhibited in : B Al Ga In Tl B < Al < Ga < In < Tl Tl < In < Ga < Al < B Tl In < Ga < Al < B The correct order of atomic radii in group 13 elements is B < Ga < Al < Tl < In B < Al < Ga < In < Tl B < Al < In < Ga < Tl B < Ga < Al < In < Tl Which of the following is incorrect statement? SnF4 is ionic in nature PbF4 is covalent in nature SiCl4 is easily hydrolysed GeX4 (X = F, Cl, Br, I) is more stable than GeX2 What is the general trend for density in Group 13 elements from Boron ( B ) to Thallium ( Tl )? Density increases regularly down the group Density decreases down the group Density first increases and then decreases Density remains almost constant Which of the following species is not stable? [ SiCl6 ] 2- [ SiF6 ] 2- [ GeCl6 ] 2- [ Sn(OH)6 ] 2- Identify the correct statements from the following : (a) CO2 (g) is used as refrigerant for ice-cream and frozen food. (b) The structure of C60 contains twelve six carbon rings and twenty five carbon rings. (c) ZSM-5, a type of zeolite, is used to convert alcohols into gasoline. (d) CO is colorless and odourless gas. (a) and (c) only (b) and (c) only (c) and (d) only (a), (b) and (c) only Taking stability as the factor, which one of the following represents correct relationship? TlCl3 > TlCl InI3 > InI AlCl > AlCl3 TlI > TlI3 Which of the following halides is most acidic? BI 3 BBr 3 BCl 3 BF 3 In Borax ( Na 2[B 4O 5(OH) 4] 8H 2O ), the number of Boron atoms that are sp 2 and sp 3 hybridized respectively are: 2, 2 1, 3 3, 1 4, 0 The electronegativity of Gallium ( Ga ) is higher than that of Aluminum ( Al ) because of: Poor shielding by 3d-electrons Smaller atomic size Inert pair effect High effective nuclear charge of Al The correct increasing order of Lewis acid strength of Boron trihalides is: BF 3 < BCl 3 < BBr 3 < BI 3 BI 3 < BBr 3 < BCl 3 < BF 3 BF 3 < BBr 3 < BCl 3 < BI 3 BCl 3 < BF 3 < BBr 3 < BI 3 Gallium has an unusually low melting point ( 303 K ) and can exist as a liquid in summer. This is attributed to: The presence of Ga 2 molecules in the crystal lattice Strong metallic bonding High ionization enthalpy The presence of vacant d-orbitals The reaction of Diborane ( B 2H 6 ) with Ammonia ( NH 3 ) in a 1:2 ratio at low temperatures initially yields: [BH 2(NH 3) 2] + [BH 4] - B 3N 3H 6 BN B 2H 6 · NH 3 The laboratory preparation of Diborane involves the reaction of: Sodium borohydride with Iodine Boron trifluoride with Lithium aluminum hydride Boron trioxide with Carbon and Chlorine Borax with Sulfuric acid In the Borax bead test, the cobalt salt gives a blue-colored bead in the oxidizing flame. This color is due to the formation of: Co(BO 2) 2 Co 3(BO 3) 2 NaCoBO 3 CoB 4O 7 Orthoboric acid ( H 3BO 3 ) acts as a much stronger acid in the presence of cis-1,2-diols such as glycerol or mannitol because: It forms stable chelate complexes with the diol, removing B(OH) 4 - from equilibrium The diol acts as a catalyst for the release of protons from the water molecule The diol reacts with H 3BO 3 to form a protonated ether species It increases the solubility of Boric acid in water, leading to higher dissociation Heating a mixture of Sodium borohydride ( NaBH 4 ) and Iodine ( I 2 ) in a high-boiling solvent yields: Diborane ( B 2H 6 ) Sodium iodide and Boron Sodium hypoborate Boron triiodide In potash alum, the ratio of K+ and SO4 2- ions is 1 : 2 2 : 1 2 : 3 3 : 2 The correct statement is Boron has a maximum covalency of four. Beryllium has three valence orbitals. Magnesium has a maximum covalency of four. Aluminium has five valence orbitals. Potash Alum ( K 2SO 4 Al 2(SO 4) 3 24H 2O ) is widely used in the purification of water. Its primary role is to: Coagulate and settle fine suspended impurities Kill bacteria and other pathogens Remove permanent hardness of water Increase the pH of acidic water The reaction of Diborane ( B 2H 6 ) with water yields: H 3B O 3 and H 2 B 2O 3 and H 2O B(OH) 4 - and H + BH 3 and H 2O The compound which is used as a primary ingredient in Borosilicate glass (Pyrex) is: B 2O 3 Al 2O 3 PbO SnO 2