NEET- THE P-BLOCK ELEMENTS – MODEL – 2024

THE P-BLOCK ELEMENTS
(GROUP 13 AND 14)

1. An example of a double salt is
(a) Bleaching powder
(b) K4 [Fe(CN)₆]
(c) Hypo
(d) Potash Alum

2. The substance used as a smoke screen in warfare is
(a) SiCl4
(b) PH3
(c) PCl5
(d) Acetylene

3. Glass is a
(a) Liquid
(b) Solid
(c) Supercooled liquid
(d) Transparent organic polymer

4. Which of the following types of forces bind together the carbon atoms in diamond?
(a) Ionic
(b) Covalent
(c) Dipolar
(d) vander Waals.

5. Water gas is produced by
(a) Passing steam through a red hot coke bed
(b) Saturating hydrogen with moisture
(c) Mixing oxygen and hydrogen in the ratio of 1: 2
(d) Heating a mixture of CO2 and CH4 in petroleum refineries.

6. Which of the following elements is extracted commercially by the electrolysis of an aqueous solution of its compound?
(a) Cl
(b) Br
(c) Al
(d) Na

7. Which of the following statements about H3BO3 is not correct?
(a) It is a strong tribasic acid
(b) It is prepared by acidifying an aqueous solution of borax
(c) It has a layer structure in which planar BO3 units are joined by hydrogen bonds
(d) It does not act as proton donor but acts as a Lewis acid by accepting a lone pair of electrons

8. In graphite, electrons are
(a) Localised on every third C-atom
(b) Present in anti-bonding orbital
(c) Localised on each C-atom
(d) Spread out between the structure

9. Glass reacts with HFto produce
(a) SiF4
(b) H2 SiF6
(c) H2 SiO3
(d) Na3AlF6

10. In borax bead test which compound is formed?
(a) Ortho-borate
(b) Meta-borate
(c) Double oxide
(d) Tetra-borate

11. Which one of the following statements about the zeolites is false?
(a) They are used as cation exchangers
(b) They have open structure which enables them to take up small molecules
(c) Zeolites are aluminosilicates having three dimensional network
(d) Some of the SiO^4-4 units are replaced by AlO45- and AlO69- ions in zeolites

12. Al2O3 can be converted to anhydrous AlCl3 by heating
(a) Al2O3 with NaCl in solid state
(b) a mixture of Al2O3 and carbon in dry Cl2 gas
(c) Al2O3 with Cl2 gas
(d) Al2O3 with HCl gas

13. The straight chain polymer is formed by:
(a) hydrolysis of CH3 SiCl3 followed by condensation polymerisation
(b) hydrolysis of (CH3)4 Si by addition polymerisation
(c) hydrolysis of (CH3)2 SiCl2 followed by condensation polymerisation
(d) hydrolysis of (CH3)3 SiCl followed by condensation polymerisation

14. The tendency of BF3, BCl3 and BBr3 to behave as Lewis acid decreases in the sequence:
(a) BCl3 > BF3 > BBr3
(b) BBr3 > BCl3 > BF3
(c) BBr3 > BF3 > BCl3
(d) BF3 > BCl3 > BBr3

15. Name the type of the structure of silicate in which one oxygen atom of [SiO4] 4– is shared?
(a) Linear chain silicate
(b) Sheet silicate
(c) Pyrosilicate
(d) Three dimensional

16. Aluminium is extracted from alumina (Al2O3) by electrolysis of a molten mixture of:
(a) Al2O3 + HF+ NaAlF4
(b) Al2O3 + CaF2 + NaAlF4
(c) Al2O3 + Na3AlF6 + CaF2
(d) Al2O3 + KF+ Na3AlF6

17. Which of the following structure is similar to graphite?
(a) B
(b) B4C
(c) B2H6
(d) BN

18. Which of these is not a monomer for a high molecular mass silicone polymer?
(a) Me2 SiCl2
(b) Me3 SiCl
(c) PhSiCl3
(d) MeSiCl3

19. The basic structural unit of silicates is:
(a) SiO4⁴⁺
(b) SiO3^2-
(c) 2 SiO4^2-
(d) SiO

20. Which statement is wrong?

(a) Feldspars are not aluminosilicates
(b) Beryl is an example of cyclic silicate
(c) Mg2 SiO4 is orthosilicate
(d) Basic structural unit in silicates is the SiO4 tetrahedron

21. Boric acid is an acid because its molecule 

(a) contains replaceable H+ ion  

(b) combines with proton from water molecule

(c) gives up a proton 

(d) accepts OH- from water releasing proton

22. Al₂O₃ on heating with carbon in an atmosphere of N2 at high temperature produces :

(a) Al₄C₃ + CO₂

(b) Al + CO₂

(c) Al + CO₂ + NO

(d) AlN + CO

23. Aluminium vessels should not be washed with materials containing washing soda since

(a)  Washing soda reats with aluminium to form insoluble aluminium oxide

(b)   Washing soda is expensive

(c)  Washing soda is easily decomposed

(d)  Washing soda reacts with aluminium to form soluble aluminate 

24. The BCl₃   is a planar molecule whereas NCl₃is pyramidal because

(a)Nitrogen atom is smaller than boron atom

(b) BCl₃ has no lone pair but NCl₃ has a lone pair of electrons

(c)B- Cl bond is more polar than N- Cl bond

(d)N – Cl bond is more covalent than B- Cl

25. The ability of a substance to assume two or more crystalline structure is called

(a)Isomerism

(b)Polymorphism

(c)Isomorphism

(d)amorphism

26. The pair of amphoteric hydroxides is

(a) Al(OH)₃, LiOH

(b) Be(OH)₂, Mg(OH)₂

(c) Zn(OH)₂, Be(OH)₂

(d) B(OH)₃, Be(OH)₂

27. Which of the following statements is incorrect?

(a) Pure sodium metal dissolves in liquid ammonia to give blue solution

(b) NaHCO₃ on heating gives Na₂CO₃

(c) NaOH reacts with glass to give sodium silicate

(d) Aluminium reacts with excess NaOH to give AI(OH)₃

28. Which one of the following is correct statement 

(a)  The hydroxide of aluminium is more acidic than that of boron

(b)  The hydroxide of boron is basic, while that of aluminium is amphoteric

(c)  The hydroxide of boron is acidic, while that of aluminium is amphoteric

(d)  The hydroxide of boron & aluminium are amphoteric

29. Which of the following oxidation states are the most characteristic for lead and tin respectively?

(a) +2,+2

(b) +4, +2

(c) +2,+4

(d) +4,+4

30. Which one of the following compounds is not a protonic acid?

(a) B(OH)₃ 

(b) PO(OH)₃

(c) SC(OH)₂ 

(d) SO₂(OH)₂

31. Aluminium is more reactive than iron. But Aluminium is less easily corroded than iron because

(a)  Aluminium is noble metal

(b)  Oxygen forms a protective oxide layer

(c)  Iron undergoes reaction easily with water

(d)   Iron forms mono and divalent ions 

32. The type of hybridisation of boron in diborane is

(a) sp-hybridisation

(b) sp³-hybridisation 

(c) sp²-hybridisation 

(d) sp³d²-hybridisation

33. An inorganic salt (A) is decomposed on heating to give two products (B) and (C). Compound (C) is a liquid at room temperature and is neutral to litmus while the compound (B) is a colourless neutral gas. Compounds (A), (B) and (C) are

(a) CaO, H₂O, CaCl₂

(b) Ba(NO₃)₂, H₂O, NO₂

(c) NH₄NO₃, N₂O, H₂O

(d) NH₄NO₂, NO, H₂O

34. The hardest substance amongst the following is 

(a)  Be₂C 

(b)  Graphite 

(c)  Titanium 

(d)  B₄C 

35. Boron compounds behave as Lewis acids, because of their

(a) ionisation property

(b) covalent nature

(c) electron deficient nature

(d) acidic nature

36. The correct formula of borax is

(a) Na₂[B₄O₆(OH)₅].7 H₂O

(b) Na₂[B₄O₇(OH)₆].6 H₂O

(c) Na₂[B₄O₄(OH)₃].9 H₂O

(d) Na₂[B4O₅(OH)₄].8 H₂O

37. Method used for obtaining highly pure silicon, used as a semiconductor material, is

(a) crystallization 

(b) zone refining

(c) oxidation 

(d) electrochemical

38. Which of the following types of forces bind together the carbon atoms in diamond?

(a) Dipolar

(b) van der Waals

(c) Ionic

(d) Covalent

39. Which of the following is an insulator ?

(a) Graphite

(b) Aluminium

(c) Diamond

(d) Silicon

40. The ability of a substance to assume two or more crystalline structures is called 

(a) polymorphism

(b) isomerism

(c) isomorphism 

(d) amorphism

41. The element Z = 114 has been discovered recently. It will belong to which of the following family/group and electronic configuration ?

(a) Carbon family, [Rn] 5f¹⁴  6d¹⁰  7s²  7p²

(b) Oxygen family, [Rn] 5f¹⁴  6d¹⁰  7s²  7p⁴

(c) Nitrogen family, [Rn] 5f¹⁴  6d¹⁰  7s²  7p⁶

(d) Halogen family, [Rn] 5f¹⁴   6d¹⁰  7s²  7p⁵

42. It is because of inability of ns2 electrons of the valence shell to participate in bonding that:-

(a) Sn²⁺   is oxidising while Pb4+ is reducing

(b) Sn²⁺  and Pb²⁺  are both oxidising and reducing

(c) Sn⁴⁺  is reducing while Pb⁴⁺  is oxidising

(d) Sn²⁺  is reducing while Pb4+ is oxidizing

43. Match the interhalogen compounds of column-I with the geometry in column II and assign the correct code.

Code :

     (1) (2) (3) (4)

(a) (iii) (i) (iv) (ii)

(b) (v) (iv) (iii) (ii)

(c) (iv) (iii) (ii) (i)

(d) (iii) (iv) (i) (ii)                

44. In which pair of ions both the species contain S.S bond?

(a)  S₄  , S₂

(b) S₂  , S₂

(c) S₄  , S₂

(d) S₄  , S₂

45. Which one of the following elements is unable to form  ion ?

(a) Ga

(b) Al

(c) In

46. Which of the following statements is not true for halogens?

(d) B                              

(a) All form monobasic oxyacids

(b) All are oxidizing agents

(c) Chlorine has the highest electron-gain enthalpy

(d) All but fluorine show positive oxidation states

47. Match the Xenon compounds in Column-I with its structure in Column-II and assign the correct code:

Column-I               Column-II

(a) XeF₄                  (i) pyramidal

(b) XeF₆                  (ii) square planar

(c) XeOF₄                (iii)distorted octahedral

(d) XeO₃                  (iv) square pyramidal

Code:

     (a) (b) (c) (d)

(1) (i) (ii) (iii) (iv)

(2) (ii) (iii) (iv) (i)

(3) (ii) (iii) (i) (iv)

(4) (iii) (iv) (i) (ii)

48. Which of the following species is not stable?

(a)  [SiF₆]^2-

(b) [GeCl₆]^2-

(c) [Sn(OH)₆]^2—

(d) [SiCl₆]^2-

49. Match the following :

          Oxide                              Nature

(a) CO                   (i) Basic

(b) BaO                  (ii) Neutral

(c) Al₂ O₃               (iii) Acidic

(d) Cl₂O₇                (iv) Amphoteric

Which of the following is correct option?

      (a) (b) (c) (d)

(1) (iii) (iv) (i) (ii)

(2) (iv) (iii) (ii) (i)

(3) (i) (ii) (iii) (iv)

(4) (ii) (i) (iv) (iii)

50. Which of the following is not correct about  carbon monoxide ?

(a) The carboxyhaemoglobin (haemoglobin bound to CO) is less stable than oxyhaemoglobin.

(b) It is produced due to incomplete combustion.

(c) It forms carboxyhaemoglobin

(d) It reduces oxygen carrying ability of blood.        

51. 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.

(1) (b) and (c) only

(2) (c) and (d) only

(3) (a), (b) and (c) only

(4) (a) and (c) only                              

52. Urea reacts with water to form A which will decompose to form B. B when passed through Cu²⁺ (aq), deep blue colour solution C is formed. What is the formula of C from the following ?

(a) Cu(OH)₂

(b) CuCO₃.Cu(OH)₂

(c) CuSO₄

(d) [Cu(NH₃)₄]²⁺

53. Which of the following oxoacid of sulphur has – O – O – linkage?

(a) H₂S₂O₈, peroxodisulphuric acid

(b) H₂S₂O₇, pyrosulphuric acid

(c) H₂SO₃, sulphurous acid

(d) H₂SO₄, sulphuric acid

54. Statement I : Acid strength increases in the order given as HF < HCl < HBr < HI.

Statement II : As the size of the elements F, Cl, Br, I increases down the group, the bond strength of HF, HCl, HBr and HI decreases and so the acid strength

increases. In the light of the above statements, choose the correct answer from the options given below.

(a) Statement I is incorrect but Statement II is true

(b) Both statement I and Statement II are true

(c) Both Statement I and Statement II are false

(d) Statement I is correct but statement II is false

55. In which one of the following arrangements the given sequence is not strictly according to the properties indicated against it?

(a) CO₂ < SiO₂ < SnO₂ < PbO₂               : Increasing oxidizing power

(b) HF < HCl < HBr < HI                      : Increasing acidic strength

(c) H₂O < H₂S < H₂Se < H₂Te                : Increasing pKa values

(d) NH₃ < PH₃ < AsH₃ < SbH₃                : Increasing acidic character

 Solutions :

1.Ans: (d) Potash Alum, K₂SO₄. Al(SO₄). 24H₂O is a double salt

2.Ans: (a) SiCl₄ gets hydrolysed in moist air and gives white fumes which are used as a smoke screen in warfare.

3.Ans: (c) Glass is super cooled liquid.

4.Ans: (b) In diamond each carbon atom is sp³ hydribized and thus forms covalent bonds with four other carbon atoms  lying at the corners of a regular tetrahedron.

5. Ans: (a) Water gas is made by blowing steam through the layer of incandescent coal.

6.Ans: (c)Aluminium can be extracted by electrolysis pure alumina (Al₂O₃) Alumina ionises as

7.Ans: (a) H₃BO₃ is a weak monobasic acid.

8.Ans: (d) In graphite , each carbon is sp²  hybridized and the single occupied unhydbridized p orbitals of Catoms overlap side wise to give π electron cloud which is delocalized and thus the electrons are spread our between the structure.

9.Ans: (b) 6HF +SiO₂ -> H₂SiF₆ +2H₂O

10.Ans: (b) On heating ,borax loses water of crystallisation and swells up to form fluffy mass. On further heating, it melts to give a clear liquid which solidifies to a transparent glossy bead consisting of sodium metaborate and boric unhydride.

11.Ans: (c) Zeolite microporous crystalline solid with well defined structure. They contain silicon, aluminium and oxygen in their framework and cations, water & other molecules within their pores. The general formula of zeolite is

M_x/y[(AlO₂)_x(SiO_­2)_y].mH₂O

12.Ans: (b) Al₂O₃ can be converted to anhydrous AlCl₃ by heating a mixture of Al₂O₃ and carbon in dry Cl₂

13.Ans: (c) Hydrolysis of substituted chlorosilanes yield corresponding silanols which undergo polymerisation.

Polymerisation of dialkyl  silandiol yields linear thermoplastic polymer.

14.Ans: (b)p-p overlap between B and F is maximum due to identical size and energy of p-orbitals, so electron deficiency in boron of BF₃ is neutralized partially to the maximum extent by back donation. Hence BF₃ is least acidic.

15.Ans: (c)

16.Ans: (c) Fused alumina(Al₂O₃) is a bad conductor of electricity. Therefore cryloite (Na₃AlF₆) and fluorspar (CaF₂) are added to purified alumina which not only make alumina a good conductor of electricity but reduce the melting point of mixture to around 1140K.

17.  Ans: (d) Boron nitride (BN) is known as inorganic graphite. The most stable form is hexagonal one. It has layered structure similar to graphite.

18.Ans: (b) Since Me₃SiCl contains only one Cl, therefore it can’t form high molecular mass silliconpolymers. It can form only dimer.

19.Ans: (a) 

20.Ans: (a) Feldspars are aluminosilicates

21.(d)Lewis acids are substances whose octet is incomplete and accepts electrons.

Boric acid is a monobasic weak acid. It does not liberate H⁺  ion but accepts electrons from OH^– ion i.e., behaves as Lewis acid.

The structure of H₃BO₃ is as shown below, where the octet of boron in H₃ BO₃ is incomplete.

22(d) Al₂ O₃  + N₂ + 3C ⟶ 2AlN + 3CO

23 (d) Aluminium vessels should not be washed with materials containing washing soda since Washing soda reacts with aluminium to form soluble aluminate .

24 (B) There is no lone pair on boron in BCl₃ hence no repulsion takes place. There is a lone pair on nitrogen in NCl₃ hence repulsion takes place.Therefore BCl₃ is planar molecular but NCl₃is pyramidal  molecule.

25(b) The phenomenon of existence of a substance in two or more crystalline structure is called polymorphism. Polymorphism of element is known as allotropy.

26 (C) Metal hydroxides with a highly-charged central metal atom can be amphoteric. Both Be(OH)₂ and Zn(OH)₂ are amphoteric in nature

27 (d) Al reacts with NaOH to give sodium metaaluminate

28 (b)  The hydroxide of boron is basic, while that of aluminium is amphoteric

29 (c) Due to inert pair effect, ns² electron pair of Pb does not participate in bonding. Thus,+2 is the most characteristic oxidation state for Pb. However, for Sn, the inert pair effect is not so strong Thus, +4 is the most characteristic oxidation state for Sn.

30 (a)

31 (b)  Oxygen forms a protective oxide layer

32 (c) boron in diborane is sp³-hybridisation 

33 (c) NH₄NO₃, N₂O, H₂O

34  (d) Boron carbide (B₄C) is one of the hardest material known, ranking third behind diamond and cubic Boron nitride.

35 (c) electron deficient nature

36 (d) Borax is sodium tetraborate decahydrate i.e. Na₂[B₄ O₅ (OH)₄ ]⋅ 8H₂ O

37 (b) Pure silicon is made by the reduction of highly purified silicon tetrachloride (SiCl₄) with dihydrogen.

SiCl₄ + 2H₂ → Si + 4HCl

The silicon obtained is purified further by the zone refining process. A method of refining metals some inorganic and organic compounds depending on the difference in solubility of impurities in the liquid and solid states is called zone refining process.

38(b)  In diamond each carbon atom is sp³ hybridized and thus forms covalent bonds with four other carbon atoms lying at the corners of a regular tetrahedron.

39 (c) Diamond

 40(a) The phenomenon of occurrence of a substance in two or more crystalline structures is called polymorphism.

41 (1) Z= 114 belongs to Group 14, carbon family Electronic configuration

42(c) The tendency of the outermost ns²  electrons of the valence shell to remain unshared and unionized in the heavier p-block elements is termed as the inert pair effect. Therefore, Pb(ll) is more stable than Pb(IV) and Sn(IV) is more stable than Sn(ll) due to inert pair effect. Due to this Pb(IV) can be easily reduced to Pb(II) and acts as an oxidising agent whereas Sn(ll) can be easily oxidised to Sn(IV) and acts as a reducing agent.

43 (a)

          XX^’   =  Linear

          XX^’₃   = T – shape

          XX^’₅    =  Square pyramidal

          XX^’₇  =  Pentagonal  Bipyramidal

44 (a)Pair of ion both the spices contain S-S bond

45(d)‘B’ has no vacant d-orbitals in its valence shell, so it can’t extend its covalency beyond 4. That means ‘B’ cannot form the ion like  i.e. .

46(d) Due to high electronegativity and small size, F forms only one oxoacid, HOF known as Fluoric (I) acid. Oxidation number of F is +1 in HOF.

47 (2)

48 (d) [SiCl₆]^2- does not exist because six large chloride ions cannot be a accommodated around Si⁴⁺due to limitation of its size.

49 (d)Generally metal oxides are basic in nature while nonmetal oxides are acidic in nature.

Neutral oxides are oxides which are neither acidic nor basic. CO is neutral oxide.

Amphoteric oxides react with both acids and alkalis to form salt and water.

Al₂​O₃​ is amphoteric oxide

50 (a) The carboxyhaemoglobin (haemoglobin bound to CO) is more stable than oxyhaemoglobin.

51  (2) Collision frequency Z₁₂   number of rectant molecular per unit volume.

54 (b) In the modern periodic table, moving down the group as the size of halogen atom increases, the H – X bond length also increases as a result the bond enthalpy decreases. Hence, The acidic strength also increases. So, the correct order of acidic strength is

HI > HBr > HCl > HF

55 (c) Stronger is the acid, lower is the value of pKa. On moving down the group, bond dissociation enthalpy of hydrides of group 16 elements decreases hence acidity increases and pKa value decreases. Correct order of pKa value will be

H₂O > H₂S > H₂Se > H₂Te