Class 12 Chemistry Sample Paper Term 1 With Solutions Set B

Please refer to Class 12 Chemistry Sample Paper Term 1 With Solutions Set B below. These Class 12 Chemistry Sample Papers will help you to get more understanding of the type of questions expected in the upcoming exams. All sample guess papers for Chemistry Class 12 have been designed as per the latest examination pattern issued by CBSE. Please practice all Term 1 CBSE Sample Papers for Chemistry in Standard 12.

Sample Paper Term 1 Class 12 Chemistry With Solutions Set B

Section A

1. Nitrogen differs from the rest of group 15 elements due to :
(A) High electronegativity
(B) High ionization enthalpy
(C) Non- availability of d-orbitals
(D) All of the above

2. The number of moles of solute dissolved in one litre of solution is called as :
(A) Molality
(B) Molarity
(C) Normality
(D) Solubility

3. Para isomers of isomeric dihalobenzene has higher melting point as compare to its ortho and meta isomers because of :
(A) loose crystal lattice structure
(B) difference in their mass
(C) change in position
(D) highly compact crystal lattice structure.

4. Ethylene dichloride is a gem-dihalide because :
(A) Cl group attached to adjacent carbon atom
(B) two carbon atoms
(C) it has both Cl present on same carbon atom
(D) none of the above

5. The correct reactant used which is oxidised to give acetone and phenol :

6. Octahedral voids are surrounded by :
(A) four spheres
(B) six spheres
(C) five spheres
(D) two spheres

7. Ethanol shows the boiling point of 351K while methoxymethane shows boiling point of only 248K.
The high boiling point of ethanol is due to :
(A) presence of intermolecular hydrogen bonding
(B) increase in size
(C) increase in molecular mass
(D) none of the above

8 When phenol is treated with conc. H₂SO₄ acid followed by treatment with conc. HNO₃, it gives :
(A) phenolic acid
(B) 2,4,6, trinitrophenol
(C) p-nitrophenol
(D) phenyl-methanoic acid

9. The possible chemical reactions of sulphuric acid are due to which of its following characteristics :
(A) strong affinity for water
(B) ability to act as an oxidising agent.
(C) low volatility
(D) all of the above

10. Which of the following is not an example of osmosis :
(A) raw mangoes shrivel when pickled in brine
(B) wilted flowers revive when placed in fresh water
(C) blood cells collapse when suspended in saline water
(D) exchange of gases in lungs

11. Starting from the given structure :

(A) iii, ii, i, iv
(B) ii, iii, iv, i
(C) i, ii, iii, iv
(D) i, iii, iv, ii

12. Covalent solids do not show which of the following property :
(A) They are very hard and brittle.
(B) They have extremely high melting point.
(C) They do not conduct electricity.
(D) They are orderly collection of positive ions surrounded by free electrons.

13. An ionic compound has a unit cell consisting of A ion at the corner of a cube and B ions on the centres of the faces of the cube. The empirical formula of the compound would be :
(A) AB
(B) A₂B
(C) AB₃
(D) A₃B

14. Liquid A and liquid B forms minimum boiling azeotrope at some specific composition. Which of the following supports the given statement :
(A) A-B interaction is stronger than those between A-A or B-B
(B) A-B interaction is weaker than that between A-A or B- B.
(C) vapour pressure of solution increases as more number of molecules of liquids A and B can escape
from solution.
(D) vapour pressure of solution decreases as less number of molecules of either liquids A or B
escape from solution

15. Which of the following carbohydrate do not follow the general formula of glucose :
(A) rhamnose
(B) cane sugar
(C) glucose
(D) fructose

16. Which of the following solution is not ideal in behaviour :
(A) n- hexane and n-heptane
(B) bromoethane and chloroethane
(C) benzene and toluene
(D) benzene and n-hexane

17. What does (i), (ii) and (iii) represent :

(A) gluconic acid , glucose and saccharic acid
(B) glucose , saccharic acid and gluconic acid
(C) glucose , gluconic acid and saccharic acid
(D) gluconic acid , saccharic acid and glucose

18. Which of the following is not an essential amino acids ?
(A) Arginine
(B) Isoleucine
(C) Valine
(D) Alanine

19. While preparing alcohols from Grignard’s reagent, the first and second step are as respectively :
(A) hydrolysis and nucleophilic addition
(B) nucleophilic addition, substitution
(C) hydrogenation, nucleophilic substitution
(D) nucleophilic addition, hydrolysis

20. A point in crystal lattice represents one constituent particle which may be :
(A) An atom
(B) A molecule
(C) An ion
(D) All of the above

21. The oxo-acid of fluorine is/are :
(A) HOF
(B) HOFO
(C) HOFO₄
(D) all of the above

22. What is not true :
(A) Rhombic sulphur is formed by evaporation.
(B) Mononclinic sulphur is formed by melting.
(C) Both rhombic and monoclinic sulphur has S₈ molecules.
(D) monoclinic sulphur is stable at room temperature.

23. Which of the following formula represents the density of a cubic unit cell ?

24. Osmotic pressure of a sugar solution in 2.46 atmosphere at 27 °C. What will be the concentration of solution in g/litre ?
(A) 26.6 g/litre
(B) 38.8 g/litre
(C) 24.2 g/litre
(D) 34.2 g/litre

25. The shape of XeO₂F₂ is :
(A) Trigonal bipyramidal
(B) Trigonal planar
(C) See-saw
(D) T-shaped

Section ‘B’

26. Which allotropic form of sulphur is most stable at room temperature :
(A) rhombic
(B) monoclinic
(C) plastic
(D) all of the above

27. The number of sulphur molecules in monoclinic and rhombic sulphur :
(A) 8,4
(B) 4,8
(C) both have 4
(D) both have 8

28. Sulphur dioxide when passed through water forms :
(A) sulphur trioxide
(B) sulphurous acid
(C) sulphuric acid
(D) sulphate

29. Choose the correct answer from the options given :

(A) Pyro sulphuric acid, Sulphuric acid, Sulphurous acid.
(B) Pyro sulphuric acid, Sulphurous acid, Sulphuric acid.
(C) Sulphuric acid, Sulphurous acid, Pyro sulphuric acid
(D) Sulphurous acid, Pyro sulphuric acid, Sulphuric acid

30. Sulphuric acid is used to manufacture more volatile acids from their corresponding salts due to its :
(A) strong reducing property
(B) strong oxidising property
(C) low volatility
(D) high volatility

31. In the complex ion [AuXe₄]²⁺, Xe acts as :
(A) central atom
(B) ligand
(C) chelating agent
(D) electrophile

32. Hybridisation shown by Au in [AuXe₄]²⁺ is :
(A) sp³
(B) sp³d
(C) sp³d²
(D) sp²

33. Compounds of noble gases except _______ are known.
(A) Krypton
(B) Radon
(C) Helium
(D) Xenon

34. Xe is a ___________ ligand.
(A) ambidentate
(B) bidentate
(C) unidentate
(D) hexadentate

35. In the formation of complex entity, the central atom acts as :
(A) Lewis acid
(B) Lewis base
(C) Bronsted acid
(D) Bronsted base

36. S_N² mechanism is not favoured when :
(A) An electrophile is attached to a methyl group
(B) A powerful nucleophile is attached
(C) In polar aprotic solvent
(D) An electrophile is attached to allylic carbon

37. Which of the following is likely to proceed with S_N¹ reaction :

38. Which of the following factors does not have any significant effect on solubility of solids in liquids ?
(A) Pressure
(B) Concentration
(C) Temperature
(D) None of these

39. Which of the following methods is must suitable for determination of molecular mass of polymers ?
(A) Vapour pressure
(B) Boiling point
(C) Osmotic pressure
(D) Freezing point

40. Mark the correct statement.
(A) Fluorine is less electronegative than chlorine
(B) Noble gases are very reactive
(C) The ionization energy of helium is very low
(D) Fluorine is a stronger oxidising agent then chlorine.

41. The acid strength of tertiary alcohol is much lesser than that of primary alcohol. It is due to presence of :
(A) Electron withdrawing group in tertiary alcohol
(B) Electron releasing group in primary alcohol
(C) Electron releasing group in tertiary alcohol
(D) None of these

42. The increasing order of boiling point of haloalkenes is :
(A) RI<RBr<RCl
(B) RCl<RBr<RI
(C) RBr<RCl<<RI
(D) RI<RCl<<RBr

43. Ethanal undergoes reduction with LiAlH4 to produce :
(A) Ethanoic acid
(B) Ethane
(C) Ethene
(D) Ethanol

44. The number of hydrogen bonds between cytosine and guanine is :
(A) 1
(B) 2
(C) 3
(D) 4

In Q.45 to Q. 49 Give one line from starting, Given below are two statements labelled as Assertion (A) and Reason (R) and at the end of each question give the following line select the must appropriate answers from the options given below :
(A) Both A and R are true and R is the correct explanation of A.
(B) Both A and R are true but R is NOT the correct explanation of A.
(C) A is true but R is false.
(D) A is false and R is true.

45. Assertion (A) : A body-centred cubic (bcc) unit cell has an atom at each of its corners and also one atom at its body centre.
Reason (R) : There are two atoms per unit cell.

46. Assertion (A) : Salmon should be included in diet.
Reason (R) : Tryptophan is an essential amino acid.

47. Assertion (A) : Nitrogen exists as diatomic molecule with a triple bond.
Reason (R) : Phosphorus and arsenic form single bonds.

48. Assertion (A) : Ethanol mixed with methanol is called as denatured alcohol.
Reason (R) : Methanol is oxidised to methanal and then to methanoic acid.

49. Assertion (A) : Wherever a sphere of the second layer is above the void of the first layer (or vice versa) a tetrahedral void is formed.
Reason (R) : The spheres of the third layer are exactly aligned with those of the first layer.

Section ‘C’

50. Match the following :

Which of the following is the best matched options ?
(A) i-A, v- B, iii- D, iv-C
(B) i-D, ii-B, iii- A, iv-C
(C) i-C, v- A, iii- D, iv-B
(D) i-C, ii- A, iii- D, iv-B

51. Which of the following analogies is correct :
(A) Chlorobenzene : Aromatic : : Phenol : Aliphatic
(B) Alcohol : Basic : : Phenol : Acidic
(C) Ethanol : Soluble in Water : : Methanol : insoluble in water
(D) Electron releasing group : decreases the acidic strength : : Electron withdrawing group : increases the acidic strength

52. Complete the following analogy :
Point defect by missing of equal number of cations and anions from lattice site : A : : Point defect by missing of one of an ion from lattice site and occupies interstitial site : B
(A) A : Frenkel defect B : Shottky defect
(B) A : Schottky defect B : Frenkel defect
(C) A : Metal excess defect B : Frenkel defect
(D) A : Metal deficiency defect B : Schottky defect

CASE 1 : Read the passage given below and answer the following questions 53-55
Nucleophiles are electron rich species. Therefore, they attack at that part of the substrate molecule which is electron deficient. The reaction in which a nucleophile replaces already existing nucleophile in a molecule is called nucleophilic substitution reaction. This reaction has been found to proceed by two different mechanisms which are described below :
In SN2 the incoming nucleophile interacts with alkyl halide causing the carbon-halide bond to break and a new bond is formed between carbon and attacking nucleophile SN1 occurs in two steps. In step I, the polarised C—Br bond undergoes slow cleavage to produce a carbocation and a bromide ion. The carbocation thus formed is then attacked by nucleophile in step II to complete the substitution reaction.

53. The preferred solvents for S_N¹ reactions are :
(A) Polar in nature
(B) Protic in nature
(C) Both polar and protic
(D) Non-polar and non protic

54. The stereochemistry in S_N¹ is ______________ while that in S_N² is______________ :
(A) Racemization, inversion
(B) Inversion, racemization
(C) Inversion, retention
(D) Retention, inversion

55. In S_N¹, the rate law depends only on :
(A) Conc. of nucleophile
(B) Conc. of the substrate
(C) Conc. of solvent
(D) All of the above