PREVIOUS YEARS
STATEMENT TYPE QUESTIONS : - -Q.5 STATEMENT-I
Although PF5, PCl5 and PBr5 are known, the pentahalides of nitrogen have not been ob-served
STATEMENT-II
Phosphorus has lower electronegativity than
nitrogen. [IIT-1994]
(A) Both statement-I and statement-II are true, and statement-II is the correct ex pla-nation of statement-I.
(B) Both statement-I and statement-II are true, but statement-II is not the correct ex-planation of statement-I
(C) statement-I is true but statement-II is false (D) statement-I is false but statement-II is
Q.8 Which of the following statements is correct for CsBr3 ? [IIT-1996]
(A) It is a covalent compound (B) It contains Cs3+ and Br– ions (C) It contains Cs+ and Br3– ions
(D) It contains Cs+ and Br– and lattice Br2 molecule
Sol.
Q.9 Hydrolysis of one mole of peroxodisulphuric acid
produces– [IIT-1996]
(A) Two moles of sulphuric acid
(B) Two moles of peroxomonosulphuric acid (C) One mole of sulphuric acid and one mole of peroxomonosulphuric acid
(D) One m ol e ea ch of sul p huri c ac i d , peroxomonosulphuric acid and hydrogen peroxide.
Sol.
Q.10 KF combines with HF to form KHF2. The com-pound contains the species : [IIT-1996]
(A) K+, F– and H+ (B) K+, F– and HF (C) K+ and [HF2]– (D) [KHF]+ and F–
Sol.
Q.11 White phosphorus (P4) has - [IIT-1998]
(A) Six P – P single bonds (B) Four P – P single bonds (C) two lone pairs of electrons (D) PPP angle of 30º
Sol.
Q.12 In Compound of type ECl3, where E = B, P As or Bi, the angles Cl – E – Cl for different E are in the order [IIT-1999]
(A) B > P = As = Bi (B) B > P > As > Bi (C) B < P = As = Bi (D) B < P < As < Bi Sol.
Q.13 On heating ammonium dichromate, the gas evolved is [IIT-1999]
(A) oxygen (B) ammonia
(C) nitrous oxide (D) nitrogen
Sol.
Q.14 One mole of calcium phosphide on reaction with excess of water gives- [IIT-1999]
(A) One mole of phosphine (B) Two moles of phosphoric acid (C) Two moles of phosphine (D) One mole of phosphorus oxide.
Sol.
Q.15 The oxidation numbers of sulphur in S8, S2F2, H2S, respectively, are – [IIT-1999]
(A) 0, + 1 and – 2 (B) + 2, + 1 and – 2 (C) 0, + 1 and + 2 (D) – 2, + 1 and – 2 Sol.
Q. 16 Ammonia can be dried by - [IIT-2000]
(A) Conc. H2SO4 (B) P4O10
(C) CaO (D)Anhydrous CaCl2
Sol.
Q. 17 The number of P – O – P bonds in cyclic meta-phosphoric acid is - [IIT-2000]
(A) Zero (B) Two
(C) Three (D) Four
Sol.
Q.18 Amongst H2O, H2S, H2Se and H2Te, the one with the highest boiling point is [IIT-2000]
(A) H2O because of hydrogen bonding (B) H2Te because of higher molecular weight (C) HsS because of hydrogen bonding (D) H2Se because of lower molecular weight
Q.19 The number of S – S bonds in sulphur trioxide trimer (S3O9) is – [IIT- 2001]
(A) Three (B) Two
(C) One (D) Zero
Sol.
Q.20 Read the following statement and explanation and answer as per the option given below :
[IIT-2001]
Statement-I : F atom has a less negative electron gain enthalpy affinity than Cl atom.
Statement-II : Additional electrons are re-pelled more effectively by 3 p electrons in Cl atom than by 2p electron in F atom
(A) If both Statement-I and Statement-II are correct, and Statement-II is the correct ex planation of the Statement-I
(B) If both Statement-I and Statement-II are correct, but Statement-II is not correct explanation of the Statement-I
(C) If I is correct but Statement-II is incorrect
(D) If I is incorrect but Statement-II is correct
Sol.
Q.21 The set with correct order of acidity is
[IIT- 2001]
(A) HClO < HCIO2 < HClO3 < HCIO4 (B) HCIO4 < HClO3 < HCIO2< HClO (C) HClO < HClO4 < HClO3 < HClO2 (D) HClO4 < HClO2 < HClO3 < HClO Sol.
(A) H3PO3 is reducing agent and dibasic acid (B) H3PO4 is reducing agent and dibasic acid (C) H3PO4 is both reducing agent and tribasic acid
(D) H3PO3 is not reducing agent and dibasic acid
Q.25 Which phosphorus is thermodynamically most
stable ? [IIT-2005]
(A) White (B) Red
(C) Black (D) Yellow
Sol.
Q.26 When two gases are mixed at 30ºC the blue coloured gas is formed [IIT-2005]
(A) N2O3 (B) N2
(C) NO2 (D) N2O5
Sol.
Passage : (Q. 27 to 29)
The noble gases have closed-shell electronic configuration and are monoatomic gases un-der normal conditions. The low boiling points of the lighter noble gases are due to weak dispersion forces between the atoms and the absence of other interatomic interactions.
The direct reaction of xenon with fluorine leads to a series of compounds with oxidation num-bers +2, +4 and +6. XeF4 reacts violently with water to give XeO3. The compounds of xenon exhibit rich stereochemistry and their geom-etries can be deduced considering the total number of electron pairs in the valence shell.
Q.27 Argon is used in arc welding because of its-(A) low reactivity with metal [IIT-2007]
(B) ability to lower the melting point of metal (C) flammability
(D) high calorific value Sol.
Q.28 The structure of XeO3 is -(A) linear (B) planar (C) pyramidal (D) T-shaped Sol.
Q.29 XeF4 and XeF6 are expected to be -(A) oxidizing (B) reducing (C) unreactive (D) strongly basic Sol.
Q.30 A solution of colourless salt H on boiling with excess NaOH produces a non-flammable gas.
The gas evolution ceases after sometime. Upon addition of Zn dust to the same solution, the gas evolution restarts. The colourless salt(s) H is (are)- [IIT-2008]
(A) NH4NO3 (B) NH4NO2
(C) NH4Cl (D) (NH4)2SO4
Sol.
Passage (Q.31 to Q.33)
There are some deposits of nitrates and phos-phates in earth’s crust. Nitrates are more soluble in water. Nitrates are difficult to re-duce under the laboratory conditions but mi-crobes do it easily. Ammonia forms large num-ber of complexes with transition metal ions.
Hybridization easily explains the ease of sigma donation capability of NH3 and PH3. Phos-phine is a flammable gas and is prepared from white phosphorous.
Q.31 Among the following, the correct statement
is-(A) Between NH3 and PH3, NH3 is a better electron donor because the lone pair of elec-trons occupies spherical ‘s’ orbital and is less directional
(B) Between NH3 and PH3, PH3 is a better electron donor because the lone pair of elec-trons occupies sp3 orbital and is more direc-tional
(C) Between NH3 and PH3, NH3 is a better lectron donor because the lone pair of elec-trons occupies sp3’ orbital and is more direc-tional
(D) Between NH3 and PH3, PH3 is a better electron donor because the lone pair of elec-trons occupies spherical ‘s’ orbital and is less directional
Sol.
Q.32 White phosphorus on reaction with NaOH gives PH3 as one of the products. This is a -(A) dimerization reaction
(B) disproportionation reaction (C) condensation reaction (D) precipitation reaction Sol.
Q.33 Aqueous solution of Na2S2O3 on reaction with Cl2 gives - [IIT-2008]
(A) Na2S4O6 (B) NaHSO4
(C) NaCl (D) NaOH
Sol.
Q.34 The reaction of P4 with X leads selectively to P4O6. The X is - [IIT-2009]
(A) Dry O2
(B) A mixture of O2 and N2 (C) Moist O2
(D) O2 in the presence of aqueous NaOH Sol.
Q.35 The nitrogen oxide(s) that contain(s) N-N bond(s) is (are) - [IIT-2009]
(A) N2O (B) N2O3
(C) N2O4 (D) N2O5
Sol.
Q.36 Match each of reactions given in Column I with the corresponding product(s) given in
ColumnII - [IIT-2009]
Column I Column II
(A ) Cu + dil HNO3 (p) NO (B) Cu + conc HNO3 (q) NO2 (C) Zn + dil HNO3 (r) N2O (D) Zn + conc HNO3 (s) Cu(NO3)2
(t) Zn(NO3)2 Sol.
Q.37 The bond energy (in kcal mol–1) of a C–C single bond is approximately [IIT-2010]
(A) 1 (B) 10
(C) 100 (D) 1000
Sol.
Q.38 All the compounds listed in Column I react with water. Match the result of the respective re-actions with the appropriate options listed in Column II. [IIT-2010]
Column I Column II
(A) (CH3)2SiCl2 (p) Hydrogen halide formation
(B) XeF4 (q) Redox reaction (C) Cl2 (r) Reacts with glass (D) VCl5 (s) Polymerization
(t) O2 formation Sol.
Q.39 Extra pure N2 can be obtained by heating-[IIT-2011]
(A) NH3 with CuO (B) NH4NO3 (C) (NH4)2Cr2O7 (D) Ba(N3)2 Sol.
Q.40 The reaction of white phosphorus with aque-ous NaOH gives phosphine along with another phosphorus containing compound. The reac-tion type ; the oxidareac-tion states of phosphorus phosphine and the other product are respec-tively
(A) redox reaction ; –3 and –5 [IIT-2012]
(B) redox reaction ; +3 and +5
(C) disproportionation reaction ; –3 and +5 (D) disproportionation reaction ; –3 and +3 Sol.