Free NEET Chemistry multiple-choice questions on Nitrogen Family (Group 15). Attempt each question and reveal the answer with a full explanation.
Which of the following elements does not form a pentahalide? Nitrogen Phosphorus Arsenic Antimony The geometry of Phosphorus pentachloride ( PCl 5 ) in the gas phase is: Trigonal bipyramidal Square pyramidal Octahedral Tetrahedral Nitrogen dioxide ( NO 2 ) exists in equilibrium with its dimer N 2O 4 . Which of the following is true regarding their colors? NO 2 is brown and N 2O 4 is colorless NO 2 is colorless and N 2O 4 is brown Both are brown Both are colorless Nitrogen differs from other members of Group 15 because it cannot form pπ–dπ bonds. This is primarily because: It lacks vacant d -orbitals in the valence shell It has very high electronegativity It has a small atomic size It has very high ionization enthalpy The basicity of Pyrophosphoric acid ( H 4P 2O 7 ) is: 4 2 3 1 In the Ostwald process for the industrial manufacture of Nitric acid, the catalyst used for the oxidation of Ammonia is: Platinum-Rhodium gauze Finely divided Iron Vanadium pentoxide Nickel Phosphine ( PH 3 ) reacts with Hydrogen iodide ( HI ) to form Phosphonium iodide ( PH 4I ). This reaction demonstrates that PH 3 is: Weakly basic Strongly basic Amphoteric Strongly acidic When an excess of Ammonia ( NH 3 ) reacts with Chlorine ( Cl 2 ), the products obtained are: NH 4Cl and N 2 NCl 3 and HCl NH 4Cl and HCl N 2 and HCl When PCl 5 is heated, it dissociates into: PCl 3 and Cl 2 PCl 2 and Cl 3 P and Cl 2 PCl 4 and Cl Nitrogen dioxide ( NO 2 ) undergoes dimerization to N 2O 4 because it: Contains an odd number of valence electrons Is a strong reducing agent Has a low bond dissociation energy Is highly electronegative Phosphorous trichloride ( PCl 3 ) fumes in moist air because it: Hydrolyzes to give HCl gas Reacts with oxygen to form POCl 3 Is highly volatile at room temperature Sublimes directly into vapor When Ammonia reacts with Cu 2+ ions in aqueous solution, it forms a deep blue complex. The formula of this complex is: [Cu(NH 3) 4] 2+ [Cu(NH 3) 6] 2+ [Cu(NH 3) 2] 2+ [Cu(NH 4) 4] 2+ Which of the following allotropes of Phosphorus is the most stable and least reactive? Black Phosphorus White Phosphorus Red Phosphorus Scarlet Phosphorus Which of the following oxides of Nitrogen is an anhydride of Nitrous acid ( HNO 2 )? N 2O 3 NO N 2O 4 N 2O 5 In the synthesis of Ammonia by Haber's process, the optimum conditions for high yield according to Le Chatelier's principle are: High Pressure and Low Temperature Low Pressure and High Temperature High Pressure and High Temperature Low Pressure and Low Temperature Among the following, the strongest Brønsted base is: NH 3 PH 3 AsH 3 SbH 3 Nitrogen exhibits a very high bond dissociation enthalpy ( 941.4 kJ/mol ) which makes it relatively inert. This is due to the presence of: A triple bond between two nitrogen atoms High electronegativity of nitrogen The presence of vacant d-orbitals Its small atomic size and high ionization enthalpy In which of the following compounds, nitrogen has the highest oxidation state? N 2O 5 NH 3 N 2H 4 HNO 2 Roasting of sulphides gives the gas X as a by-product. This is a colorless gas with choking smell of burnt sulphur and causes great damage to respiratory organs as a result of acid rain. Its aqueous solution is acidic acts as a reducing agent and its acid has never been isolated. The gas X is H2S SO2 CO2 SO3 The basic structural unit of silicates is SiO - SiO4 4- SiO3 2- SiO4 2- Which of the following is electron-deficient? (CH3)2 (SiH3)2 (BH3)2 PH3 Which of these is not a monomer for a high molecular mass silicone polymer? MeSiCl3 Me2SiCl2 Me3SiCl PhSiCl3 Hydrolysis of Magnesium nitride ( Mg 3N 2 ) produces which gas? NH 3 N 2 H 2 NO When copper is heated with conc. HNO3 it produces Cu(NO3)2 and NO2 Cu(NO3)2 and NO Cu(NO3)2 , NO and NO2 Cu(NO3)2 and N2O The product obtained as a result of a reaction of nitrogen with CaC2 is :- Ca(CN)2 CaCN CaCN3 Ca2CN Which is the correct statement for the given acids? Phosphinic acid is a diprotic acid while phosphonic acid is a monoprotic acid Phosphinic acid is a monoprotic acid while phosphonic acid is a diprotic acid Both are triprotic acids Both are diprotic acids Strong reducing behaviour of H3PO2 is due to Low coordination number of P Low oxidation state of P Presence of one –OH group and two P–H bonds Presence of two –OH groups and one P–H bonds Match the following : Which of the following is the correct option? array ll (a) Pure nitrogen & (i) Chlorine (b) Haber process & (ii) Sulphuric acid (c) Contact process & (iii) Ammonia (d) Deacon’s process & (iv) Sodium azide or Barium azide array (iv) (iii) (ii) (i) (i) (ii) (iii) (iv) (ii) (iv) (i) (iii) (iii) (iv) (ii) (i) Which of the following oxoacid of sulphur has - O-O - linkage? H2SO4 , sulphuric acid H2S2O8 , peroxodisulphuric acid H2S2O7 , pyrosulphuric acid H2SO3 , sulphurous acid The maximum temperature that can be achieved in blast furnace is : Upto 2200 K Upto 1900 K Upto 5000 K Upto 1200 K White phosphorus is more reactive than red phosphorus because: It possesses angular strain in P 4 molecule It is more metallic It has a polymeric structure It contains P=P double bonds Which of the following oxoacids of phosphorus is a powerful reducing agent due to P-H bonds? H 3PO 2 H 3PO 4 H 4P 2O 7 HPO 3 Pure nitrogen gas can be prepared in the laboratory by the thermal decomposition of: Ba(N 3) 2 NH 4NO 3 NH 4Cl (NH 4) 2SO 4 Nitrogen molecule ( N 2 ) is chemically inert at room temperature because of: High bond dissociation enthalpy Absence of d-orbitals Small atomic size High electronegativity When P 4 is heated with concentrated NaOH solution in an inert atmosphere of CO 2 , the products are: PH 3 and NaH 2P 2 PH 3 and Na 2HPO 3 PH 3 and NaH 2PO 2 PCl 3 and NaOH Which of the following is the most powerful reducing agent among Group 15 hydrides? BiH 3 SbH 3 AsH 3 NH 3 The bond angle in PH 3 is: Much smaller than NH 3 Greater than NH 3 Equal to NH 3 Exactly 109.5 What is the basicity of orthophosphorous acid ( H 3PO 3 )? 2 1 3 0 In the reaction 3Cu + 8HNO 3(dilute) 3Cu(NO 3) 2 + X + 4H 2O , identify X : NO NO 2 N 2O N 2 When Ammonia ( NH 3 ) reacts with an excess of Chlorine ( Cl 2 ), the products formed are: NCl 3 and HCl NH 4Cl and N 2 N 2 and HCl NH 4Cl and NCl 3 In the solid state, Phosphorus pentachloride ( PCl 5 ) exists as: [PCl 4] + [PCl 6] - [PCl 3] + [PCl 7] - P 2Cl 10 dimer [PCl 5] 2 clusters How many P-O-P bonds are present in the molecule of Phosphorus trioxide ( P 4O 6 )? 6 4 3 10 What is the oxidation state of Phosphorus in Pyrophosphorous acid ( H 4P 2O 5 )? +3 +1 +4 +5 When Phosphine ( PH 3 ) is passed through a solution of Copper sulfate ( CuSO 4 ), it forms a black precipitate of: Cu 3P 2 CuP Cu 2P Cu 3(PO 4) 2 Thermal decomposition of Ammonium nitrate ( NH 4NO 3 ) produces: N 2O N 2 NO NO 2 Phosphine is used in 'Holme's signals' because it: Spontaneously ignites in contact with air Has a very pleasant smell Is highly soluble in water Is extremely non-flammable Nitrogen dioxide ( NO 2 ) gas is paramagnetic and brown, but on cooling it becomes a colorless solid. This is because: It dimerizes to N 2O 4 which has all paired electrons It reacts with moisture in the air The oxidation state of Nitrogen changes from +4 to +3 It undergoes a phase change to a metallic lattice Which of the following has the smallest bond angle? SbH 3 NH 3 PH 3 AsH 3 Red phosphorus is less reactive than white phosphorus because: It has a polymeric structure consisting of chains of P 4 tetrahedra It has a lower boiling point It is soluble in Carbon disulfide ( CS 2 ) It exists as discrete P 2 molecules Hydrolysis of Phosphorus trichloride ( PCl 3 ) yields: H 3PO 3 + HCl H 3PO 4 + HCl PH 3 + HCl POCl 3 + HCl Very pure Nitrogen ( >99.9 % ) can be obtained by the thermal decomposition of: Barium azide ( Ba(N 3) 2 ) Ammonium dichromate ( (NH 4) 2Cr 2O 7 ) Ammonium chloride and Sodium nitrite Ammonia with Bleaching powder What is the maximum covalency that Nitrogen can exhibit in its compounds? 4 3 5 6 When Nitrogen gas is passed over Calcium Carbide ( CaC 2 ) at very high temperatures ( 1100 C ), the product formed is known as 'Nitrolim'. What is its formula? CaCN 2 + C Ca(CN) 2 Ca(NH 2) 2 CaN 2 White phosphorus ( P 4 ) reacts with Sulfuryl chloride ( SO 2Cl 2 ) to produce: PCl 5 and SO 2 PCl 3 and SO 2 POCl 3 and S 2Cl 2 PCl 5 and SCl 2 Phosphine ( PH 3 ) prepared in the laboratory from Calcium phosphide and water is often spontaneously flammable. This is due to the presence of traces of: P 2H 4 or P 4 vapors PH 4OH P 2O 5 H 3PO 2 In the gas phase, the molecule PCl 5 has the geometry of a: Trigonal bipyramid Square pyramid Pentagonal planar Octahedron Which oxide of Nitrogen is a blue solid at very low temperatures and exists as a liquid at room temperature under pressure? N 2O 3 N 2O NO 2 N 2O 5 What is the number of N-N bonds and the oxidation state of Nitrogen in N 2O 3 ? 1 N-N bond; oxidation state +3 0 N-N bonds; oxidation state +3 1 N-N bond; oxidation state +2 2 N-N bonds; oxidation state +4 When White Phosphorus ( P 4 ) reacts with concentrated Nitric acid ( HNO 3 ), the products formed are: H 3PO 4 and NO 2 H 3PO 3 and NO P 4O 10 and N 2O PH 3 and NO 2 What is the equivalent weight of Phosphorous acid ( H 3PO 3 ) in a neutralization reaction with excess NaOH ? ( M = Molar mass ) M/2 M/1 M/3 M/4 The bond order of CO and NO + are respectively: 3 and 3 2 and 3 3 and 2 2.5 and 2.5 The bond angle H-P-H in Phosphine ( PH 3 ) is close to: 93 ∘ 107 ∘ 104.5 ∘ 120 ∘ The gas produced when Calcium Cyanamide ( CaNCN ) is treated with superheated steam is: Ammonia ( NH 3 ) Nitrogen ( N 2 ) Nitric Oxide ( NO ) Cyanogen ( C 2N 2 ) The laughing gas ( N 2O ) is prepared in the laboratory by heating a mixture of: Ammonium sulfate and Sodium nitrate Ammonium chloride and Sodium nitrite Ammonium chloride and Sodium nitrate Ammonium nitrite and Sodium hydroxide In the reaction P 4 + 20HNO 3(conc.) X + 20NO 2 + 4H 2O , the compound X is: H 3PO 4 H 3PO 3 P 4O 10 HPO 3 What is the correct structure of Phosphorus acid ( H 3PO 3 )? Two P-OH bonds, one P-H bond, and one P=O bond Three P-OH bonds and one P=O bond One P-OH bond, two P-H bonds, and one P=O bond Three P-OH bonds and one lone pair In the Haber's process for the manufacture of Ammonia, Molybdenum ( Mo ) is used as: A catalytic promoter A catalyst A catalytic poison An oxidizing agent When concentrated Nitric acid ( HNO 3 ) reacts with White Phosphorus ( P 4 ), the final phosphorus-containing product is: Orthophosphoric acid ( H 3PO 4 ) Phosphorous acid ( H 3PO 3 ) Phosphorus pentoxide ( P 4O 10 ) Phosphine ( PH 3 ) In the gaseous PCl 5 molecule, the axial P-Cl bonds are longer than the equatorial P-Cl bonds because: Axial bonds suffer more repulsion from equatorial bond pairs Axial bonds have more s-character Equatorial bonds are more constrained by lone pairs Axial bonds are formed by d -orbitals only Hypophosphorous acid ( H 3PO 2 ) is a strong reducing agent. It reduces Silver nitrate ( AgNO 3 ) to: Metallic Silver Silver oxide Silver phosphide Silver nitrite Which of the following is a byproduct in the industrial manufacture of Phosphine ( PH 3 ) from White Phosphorus and NaOH ? NaH 2PO 2 Na 3PO 4 P 2H 4 H 3PO 4 In the nitration of benzene, concentrated Sulfuric acid ( H 2SO 4 ) is added to concentrated Nitric acid ( HNO 3 ). The role of H 2SO 4 here is to act as a/an: Brønsted acid Brønsted base Reducing agent Inert solvent Al2O3 can be converted to anhydrous AlCl3 by heating:- Al2O3 with HCl gas Al2O3 with NaCl in solid state A mixture of Al2O3 and carbon in dry Cl2 gas Al2O3 with Cl2 gas Match List-I with List-II : array ll List-I (Oxoacids of Sulphur) & List-II (Bonds) A. Peroxodisulphuric acid & I. Two S–OH, Four S=O, One S–O–S B. Sulphuric acid & II. Two S–OH, One S=O C. Pyrosulphuric acid & III. Two S–OH, Four S=O, One S–O–O–S D. Sulphurous acid & IV. Two S–OH, Two S=O array Choose the correct answer from the options given below. A–I, B–III, C–II, D–IV A–III, B–IV, C–I, D–II A–I, B–III, C–IV, D–II A–III, B–IV, C–II, D–I Which gas is released when Zinc reacts with very dilute Nitric acid ( HNO 3 )? N 2O NO NO 2 NH 4NO 3 The brown ring test for nitrates is due to the formation of a complex with the formula: [Fe(H 2O) 5(NO)] 2+ [Fe(H 2O) 5(NO 2)] 2+ [Fe(H 2O) 6] 2+ [Fe(CN) 5(NO)] 2- Which of the following phosphorus oxoacids contains a P-P linkage? H 4P 2O 6 H 4P 2O 7 H 4P 2O 8 H 3PO 4 Hypophosphorous acid ( H 3PO 2 ) is a good reducing agent because it contains: Two P-H bonds Two P-OH bonds One P-H bond One P=O bond What is the number of P-O-P bonds in phosphorus pentoxide ( P 4O 10 )? 6 4 5 10 The compound formed when Nessler's reagent reacts with ammonia is: NH 2.HgO.HgI K 2[HgI 4] Hg(NH 2)Cl HgNH 2I White phosphorus ( P 4 ) reacts with thionyl chloride ( SOCl 2 ) to produce which of the following phosphorus halides? PCl 3 PCl 5 POCl 3 P 2Cl 4 How many oxygen atoms are shared between two Phosphorus atoms (bridging) in a molecule of P 4O 10 ? 6 4 10 2 In the solid state, Dinitrogen pentoxide ( N 2O 5 ) exists as an ionic compound with the structure: [NO 2] + [NO 3] - [NO] + [NO 3] - [NO 2] + [NO 2] - [N 2O] + [O 4] - The dipole moment of NF 3 is much smaller than that of NH 3 because: The orbital dipole and bond dipoles oppose each other in NF 3 The orbital dipole and bond dipoles reinforce each other in NF 3 Fluorine is less electronegative than Hydrogen Nitrogen is sp 2 hybridized in NF 3 In the hydrolysis of Nitrogen trichloride ( NCl 3 ), the products are different from the hydrolysis of Phosphorus trichloride ( PCl 3 ). The products of NCl 3 hydrolysis are: NH 3 and HOCl HNO 3 and HCl NH 3 and HCl N 2 and HCl Which of the following is the correct order of the boiling points of Group 15 hydrides? PH 3 < AsH 3 < NH 3 < SbH 3 < BiH 3 NH 3 < PH 3 < AsH 3 < SbH 3 < BiH 3 PH 3 < NH 3 < AsH 3 < SbH 3 < BiH 3 BiH 3 < SbH 3 < AsH 3 < PH 3 < NH 3 The reaction of Phosphine ( PH 3 ) with a solution of Silver nitrate ( AgNO 3 ) results in the formation of: Metallic Silver Silver Phosphide ( Ag 3P ) Silver Oxide ( Ag 2O ) Phosphoric acid and Nitrogen Which of the following oxides of Nitrogen is an odd-electron molecule and exists as a blue solid in the condensed phase? NO NO 2 N 2O 3 N 2O The number of P-OH bonds in orthophosphoric acid ( H 3PO 4 ) is: 3 2 1 0