Bihar Board 12th Chemistry Objective Important Questions Part 1 in English
Bihar Board 12th Chemistry Objective Important Questions Part 1 in English
Question 1.
Number of σ and π Bonds in C2 Molecule is/are :
(a) 1σ and 1π
(b) 1σ and 2π
(c) 2π only
(d) 1σ and 3π
Answer:
(c) 2π only
Question 2.
The correct order of equivalent conductance of infinite dilution of LiCl, NaCl and KCl is :
(a) LiCl > NaCl > KCl
(b) KCl > NaCl > LiCl
(c) NaCl > KCl > LiCl
(d) LiCl > KCl > NaCl
Answer:
(b) KCl > NaCl > LiCl
Question 3.
The Molecule which has zero dipole moment is :
(a) NF3
(b) BF3
(c) CrO3
(d) CH2Cl2
Answer:
(b) BF3
Question 4.
A Dilute aqueous solution of’ sodium Fluoride is Electrolyzed the products at the anode and cathode are :
(a) F2, Na
(b) F2, H2
(c) O2, Na
(d) O2, H2
Answer:
(a) F2, Na
Question 5.
R-OH + CH2N2 → Leaving group in this reaction is :
(a) CH3
(b) R
(c) N2
(d) CH2
Answer:
(c) N2
Question 6.
The Product obtained when silica reacts with hydrogen Fluoride is :
(a) SiF4
(b) H2SiF6
(c) H2SiF4
(d) H2SiF3
Answer:
(a) SiF4
Question 7.
The Vant Hoffs factor of 0.1M Ba(NO3)2 solution is 2.74. The Degree of dissociation is:
(a) 91.3%
(b) 87%
(c) 100%
(d) 74%
Answer:
(b) 87%
Question 8.
Which of the following has the most stable +2 oxidation state :
(a) Sn
(b) Ag
(c) Fe
(d) Pb
Answer:
(d) Pb
Question 9.
Cannizzaro’s reaction is not given by :
(a) Formaldehyde
(b) Acetaldehyde
(c) Benzaldehyde
(d) Furfural
Answer:
(b) Acetaldehyde
Question 10.
Which Gas is absorbed strongly by charcoal :
(a) CO
(b) NH3
(c) NCl3
(d) H2
Answer:
(b) NH3
Question 11.
An organic compound gives Iodoform test and also gives positive test with Tollen reagent the compound is :
(a) CH3CHO
(c) CH3CH2OH
(d) (CH3)2CHOH
Answer:
(a) CH3CHO
Question 12.
Which Alkyl halide follows only SN2 hydrolysis Mechanism :
(a) CH3CH2-X
(b) (CH3)2CHX
(c) (CH3)3C-X
(d) C6H5CH2X
Answer:
(a) CH3CH2-X
Question 13.
The most stable oxidation states of Bismuth is :
(a) +3
(b) +5
(c) +3 and +5 Both
(d) None
Answer:
(a) +3
Question 14.
In Which of the following pairs of structure are tetrahedral as well as octahedral void respectively :
(a) B.C.C. and f.c.c.
(b) hcp and simple cubre
(c) hcp and ccp
(d) bcc and hcp
Answer:
(c) hcp and ccp
Question 15.
Which one of the following is Non-Crystalline or Amorphous :
(a) Diamond
(b) Graphite
(c) Glass
(d) Common salt
Answer:
(c) Glass
Question 16.
Which one of the following will produce maximum depression of freezing point:
(a) K2SO4
(b) NaCl
(c) Urea
(d) Glucose
Answer:
(a) K2SO4
Question 17.
If 2 gram of NaOH is present in 200 ml of its solution. Its molarity will be:
(a) 0.25
(b) 0.5
(c) 5
(d) 10
Answer:
(a) 0.25
Question 18.
Fused NaCl on Electrolysis gives on Cathode :
(a) Chlorine
(b) Sodium
(c) Sodium amalgam
(d) Hydrogen
Answer:
(b) Sodium
Question 19.
If 96500 Coulomb of Electricity is passed through CuSO4 solution it will liberate :
(a) 63.5 gm Cu
(b) 31.76 gm Cu
(c) 96500 gm Cu
(d) 100 gm Cu
Answer:
(b) 31.76 gm Cu
Question 20.
If the Rate of a reaction is expressed by-
Rate = K [A]2 [B] the order of reaction will be :
(a) 2
(b) 3
(c) 1
(d) 0
Answer:
(b) 3
Question 21.
Which one of the following Elements is found in Free state in Nature ?
(a) Sodium
(b) Iron
(c) Zinc
(d) Gold
Answer:
(d) Gold
Question 22.
Which one of the following does not form hydrogen-bonding ?
(a) NH3
(b) H2O
(c) HCl
(d) HF
Answer:
(c) HCl
Question 23.
Main source of Heliumis :
(a) Air
(b) Radium
(c) Monazite
(d) Water
Answer:
(c) Monazite
Question 24.
Which one of the following is diamagnetic ion :
(a) Co2+
(b) Ni2+
(c) Cu2+
(d) Zn2+
Answer:
(d) Zn2+
Question 25.
Antiferro magnetic oxide is :
(a) MnO2
(b) TiO2
(c) VO2
(d) CrO2
Answer:
(d) CrO2
Question 26.
Milk is an example of :
(a) Emulsion
(b) Suspension
(c) beam
(d) sol
Answer:
(a) Emulsion
Question 27.
Which of the following solution (in water) has highest boiling point:
(a) 1 M NaCl
(b) 1 M MgCl2
(c) 1 M Urea
(d) 1 M Glucose
Answer:
(b) 1 M MgCl2
Question 28.
Which of the following is Natural fibre :
(a) Starch
(b) Cellulose
(c) Rubber
(d) Nalon-6
Answer:
(b) Cellulose
Question 29.
Number of atoms in b.c.c unit cell is :
(a) 1
(b) 2
(c) 3
(d) 4
Answer:
(b) 2
Question 30.
Number of atoms in simple cubic unit cell is :
(a) 1
(b) 2
(c) 3
(d) 4
Answer:
(a) 1
Question 31.
Number of atoms in f.c.c. unit cell is :
(a) 1
(b) 2
(c) 3
(d) 4
Answer:
(d) 4
Question 32.
Number of Tetrahederal voids in per unit cell of f.c.c. structure contain same atoms :
(a) 4
(b) 6
(c) 8
(d) 12
Answer:
(c) 8
Question 33.
5 gram Glucose dissolved in 20 gram water, What percentage mass of solution :
(a) 25%
(b) 20%
(c) 5%
(d) 4%
Answer:
(b) 20%
Question 34.
The property of the solution does not depend on Temperature :
(a) Molarity
(b) Molality
(c) Normality
(d) Density
Answer:
(b) Molality
Question 35.
What is molality of water at 25°C is :
(a) 18 Mole Litre-1
(b) 10-7 Mole Litre-1
(c) 55.5 Mole Litre-1
(d) None of these
Answer:
(c) 55.5 Mole Litre-1
Question 36.
Buna-s is :
(a) Natural polymer
(b) Synthetic polymer
(c) Sulphur polymer
(d) None of these
Answer:
(b) Synthetic polymer
Question 37.
Nylon 66 is polyamide of:
(a) Vinyl chloride and formaldehyde
(b) adipic acid and methylamine
(c) adipic acid and hexamethylene diamine
(d) formaldehyde and melamine
Answer:
(c) adipic acid and hexamethylene diamine
Question 38.
Monomer of PVC is :
(a) Ethylene
(b) Tetrafluoroethylene
(c) Chloroethene
(d) None of these
Answer:
(c) Chloroethene
Question 39.
The function of flux during smelting of the ore is :
(a) To make the ore porous
(b) To facilitate reduction
(c) To remove gangue
(d) To facilitate oxidation
Answer:
(c) To remove gangue
Question 40.
Froth floatation process is based on :
(a) specific gravity of the ore particles
(b) Magnetic properties of the ore particles
(c) Electrical properties of the ore particles
(d) wetting properties of the ore particles
Answer:
(d) wetting properties of the ore particles
Question 41.
Carbon monoxide reduction process is used for the extraction of:
(a) Sn
(b) Ag
(c) Cu
(d) Fe
Answer:
(d) Fe
Question 42.
Argentite is a mineral of:
(a) Cu
(b) Ag
(c) Au
(d) Pt
Answer:
(b) Ag
Question 43.
Heating of pyrites to remove sulphur is called as :
(a) Roasting
(b) Smelting
(c) Calcination
(d) Fluxing
Answer:
(a) Roasting
Question 44.
Wood spirit is known as :
(a) Methanol
(b) Ethanol
(c) Acetone
(d) Acetic acid
Answer:
(a) Methanol
Question 45.
Which of the following does not reduces Fehling’s solution?
(a) Formic acid
(b) Acetic acid
(c) Acetaldehyde
(d) Formaldehyde
Answer:
(b) Acetic acid
Question 46.
Intermolecular hydrogen bonding is strongest in :
(a) Methylamine
(b) Phenol
(c) Methanol
(d) Formaldehyde
Answer:
(c) Methanol