Bihar Board 12th Chemistry VVI Objective Questions Model Set 2 in English

Bihar Board 12th Chemistry Objective Questions and Answers

Bihar Board 12th Chemistry VVI Objective Questions Model Set 2 in English

Question 1.
Nitrogen is used to fill electric bulbs because
(a) it is lighter than air
(b) it makes the bulb to glow
(c) it does not support combustion
(d) it is non-toxic
Answer:
(c) it does not support combustion

Question 2.
Which of the following compounds will not give amount on heating?
(a) (NH₄)₂SO₄
(b) (NH₄)₂CO₃
(c) NH₄NO₂
(d) NH₄Cl
Answer:
(c) NH₄NO₂

Question 3.
Identify the species in which the metal atom is in +6 oxidation state
(a) MnO^–₄
(b) [Cr(CN)₆]^3-
(c) [NiF₆]^2-
(d) CrO₂Cl₂
Answer:
(d) CrO₂Cl₂

Question 4.
In which of the following compounds manganese has oxidation number equal to that of iodine in KIO₄?
(a) Potassium manganate
(b) Potassium permanganate
(c) Manganous chloride
(d) Manganese chloride
Answer:
(b) Potassium permanganate

Question 5.
Among the following, which are ambidentate ligands?
(i) SCN^–
(ii) NO₃^–
(iii) NO₂^–
(iv) C₂O₄^2-
(a) (i) and (iii)
(b) (i) and (iv)
(c) (ii) and (iii)
(d) (ii) and (iv)
Answer:
(a) (i) and (iii)

Question 6.
Which of the following ligands form a chelate?
(a) Acetate
(b) Oxalate
(c) Cyanide
(d) Ammonia
Answer:
(b) Oxalate

Question 7.
Which of the following compounds can yield only one monochlorinated product upon free radical chlorination?
(a) 2, 2-Dimethylpropane
(b) 2-Methylpropane
(c) 2-Methylbutance
(d) n-Butane
Answer:
(a) 2, 2-Dimethylpropane

Question 8.
Bromination of methane in the presence of sunlight is a
(a) nucleophilic substitution
(b) free radical substitution
(c) electrophilic substitution
(d) nucleophilic addition
Answer:
(b) free radical substitution

Question 9.
Which reducing agent is used for the following conversion?
RCOOH → RCH₂OH
(a) LiAlH₄
(b) NaBH₄
(c) K₂Cr₂O₇
(d) KMnO₄
Answer:
(a) LiAlH₄

Question 10.
Tertiary butyl alcohol can be prepared by the reaction of
(a) acetaldehyde and ethyl magnesium iodide
(b) acetone and methyl magnesium iodide
(c) formaldehyde and propyl magnesium iodide
(d) butanone and methyl magnesium iodide
Answer:
(b) acetone and methyl magnesium iodide

Question 11.
There is a large difference in the boiling points of butanal and butan-1-ol due to
(a) intermolecular hydrogen bonding in butan-1-ol
(b) intramolecular hydrogen bonding in butanal
(c) the higher molecular mass of butan-1-ol
(d) resonance showed by butanal
Answer:
(a) intermolecular hydrogen bonding in butan-1-ol

Question 12.
Choose the correct statement regarding the physical properties of carbonyl compounds.
(a) All aldehydes are insoluble in benzene.
(b) Higher aldehydes are more fragrant
(c) n-Butane has more boiling point than acetone
(d) Methanal and propanone are immiscible with water in all proportions.
Answer:
(b) Higher aldehydes are more fragrant

Question 13.
Reduction of CH₃CH₂NC with hydrogen in the presence of Ni or Pt as catalyst gives
(a) CH₃CH₂NH₂
(b) CH₃CH₂NHCH₃
(c) CH₃CH₂NHCH₂CH₃
(d) (CH₃)₃N
Answer:
(b) CH₃CH₂NHCH₃

Question 14.
What is the end product in the following sequence of reaction?
Bihar Board 12th Chemistry VVI Objective Questions Model Set 2 in English Q14
(a) Aniline
(b) Phenol
(c) Benzene
(d) Benzenediazonium chloride
Answer:
(a) Aniline

Question 15.
During the acetylation of glucose, it needs x moles of acetic anhydride. The value of x would be
(a) 3
(b) 5
(c) 4
(d) 1
Answer:
(b) 5

Question 16.
The letter ‘D’ in carbohydrates signifies
(a) dextrorotatory
(b) configuration
(c) diamagnetic nature
(d) mode of synthesis
Answer:
(b) configuration

Question 17.
Which of the following are thermoplastic polymers?
(a) Polythene, urea-formaldehyde, polyvinyls
(b) Bakelite, polythene, polystyrene
(c) Polythene, polystyrene, polyvinyl
(d) Urea-formaldehyde, polystyrene, bakelite
Answer:
(c) Polythene, polystyrene, polyvinyl

Question 18.
Which of the following is not a characteristic of thermosetting polymers?
(a) Linear or slightly branched long-chain polymers
(b) Heavily branched and cross-linked polymers
(c) Become infusible on moulding
(d) Cannot be remoulded or reused on heating
Answer:
(a) Linear or slightly branched long-chain polymers

Question 19.
Which of the following is not acts as a tranquillizer?
(a) Equanil
(b) Analgin
(c) Meprobamate
(d) Chlordiazepoxide
Answer:
(b) Analgin

Question 20.
Which of the following is the scientific explanation of depression?
(a) An increased level of sugar in the blood leads to depression.
(b) Low levels of noradrenaline, a neurotransmitter in the blood lead to depression.
(c) Release of extra gastric juice in the stomach leads to depression.
(d) Sleep inducing drugs lead to depression.
Answer:
(b) Low levels of noradrenaline, a neurotransmitter in the blood lead to depression.

Question 21.
How many chloride ions are surrounding sodium ion in sodium chloride crystal?
(a) 4
(b) 8
(c) 6
(d) 12
Answer:
(c) 6

Question 22.
In the NaCl structure,
(a) all octahedral and tetrahedral sites are occupied
(b) only octahedral sites are occupied
(c) only tetrahedral sites are occupied
(d) neither octahedral nor tetrahedral sites are occupied.
Answer:
(b) only octahedral sites are occupied

Question 23.
NaCl type crystal (with coordination no. 6 : 6) can be converted into CsCl type crystal (with coordination no. 8 : 8) by applying
(a) high temperature
(b) high pressure
(c) high temperature and high pressure
(d) low temperature and low pressure.
Answer:
(b) high pressure

Question 24.
Coordination numbers of Cs⁺ and Cl^– in CsCl crystal are
(a) 8, 8
(b) 4, 4
(c) 6, 6
(d) 8, 4
Answer:
(a) 8, 8

Question 25.
Which of the following statements is not true?
(a) Silicon carbide is a covalent crystal.
(b) Molecular crystals are soft in nature.
(c) In the calcium fluoride structure, the coordination number of Ca²⁺ is 4.
(d) Increase in radius ratio results in an increase in coordination number.
Answer:
(c) In the calcium fluoride structure, the coordination number of Ca²⁺ is 4.

Question 26.
What will be the molarity of 30 mL of 0.5 M H₂SO₄ solution diluted to 500 mL?
(a) 0.3 M
(b) 0.03 M
(c) 3 M
(d) 0.103 M
Answer:
(b) 0.03 M

Question 27.
How many Na⁺ ions are present in 100 mL of 0.25 M of NaCl solution?
(a) 0.025 × 10²³
(b) 1.505 × 10²²
(c) 15 × 10²²
(d) 2.5 × 10²³
Answer:
(b) 1.505 × 10²²

Question 28.
Which of the following is the correct order in which metals displace each other from the salt solution of their salts?
(a) Zn, Al, Mg, Fe, Cu
(b) Cu, Fe, Mg, Al, Zn
(c) Mg, Al, Zn, Fe, Cu
(d) Al, Mg, Fe, Cu, Zn
Answer:
(c) Mg, Al, Zn, Fe, Cu

Question 29.
Zn gives hydrogen with H₂SO₄ and HCl but not with HNO₃ because
(a) Zn acts as an oxidising agent when reacts with HNO₃
(b) HNO₃ is a weaker acid than H₂SO₄ and HCl
(c) Zn is above the hydrogen in electrochemical series
(d) NO₃ is reduced in preference to H⁺ ion.
Answer:
(d) NO₃ is reduced in preference to H⁺ ion.

Question 30.
The rate constant of a reaction depends upon
(a) the temperature of the reaction
(b) the extent of the reaction
(c) the initial concentration of the reaction
(d) the time of completion of the reaction
Answer:
(a) the temperature of the reaction

Question 31.
The chemical reaction, 2O₃ → 3O₂ proceeds as
O₃ ↔ O₂ + [O] (fast)
[O] + O₃ → 2O₂ (slow)
The rate law expression will be
(a) Rate = k[O] [O₃]
(b) Rate = k[O₃]² [O₂]^-1
(c) Rate = k[O₃]²
(d) Rate = k[O₂] [O]
Answer:
(b) Rate = k[O₃]² [O₂]^-1

Question 32.
Which of the following gases is least absorbed on charcoal?
(a) HCl
(b) NH₃
(c) O₂
(d) CO₂
Answer:
(c) O₂

Question 33.
Which of the following is not characteristic of chemisorption?
(a) Adsorption is specific
(b) The heat of adsorption is of the order of 200 kJ mol^-1
(c) Adsorption is irreversible
(d) Adsorption may be multimolecular layers
Answer:
(d) Adsorption may be multimolecular layers

Question 34.
Which one of the following is not a sulphide ore?
(a) Galena
(b) Iron pyrites
(c) Magnetite
(d) Copper glance
Answer:
(c) Magnetite

Question 35.
Which of the following is a halide ore?
(a) Cassiterite
(b) Anglesite
(c) Siderite
(d) Camallite
Answer:
(d) Camallite