PSC HSST Chemistry Junior Model Questions and Answers

26. The law of constancy of interfacial angle is called :
(A) Hauy’s law
(B) Law of symmetry
(C) Steno’s law
(D) Miller’s law
Answer: C

27. Which of the following complex ions would have the smallest crystal field splitting?
(A) [Co(NH3)6]3+
(B) [Rh(NH3)6]2+
(C) [Ir(NH3)6]2+
(D) [Co(NH3)6]2+
Answer: D

28. A plot of log[A] Vs time(t) gives a straight line with negative slope. The order of the reaction is :
(A) 0
(B) 1
(C) 2
(D) 3
Answer: B

29. The nature of electronic spectra of ‘d’ block elements is mainly due to :
(A) Incomplete d-orbitals
(B) Term splitting in different crystal field geometry
(C) Presence of hydrated ions
(D) Removal of degeneracy of d-orbitals
Answer: A

30. How many Bravais lattices can exist in nature?
(A) 32
(B) 17
(C) 14
(D) 7
Answer: C

31. How many ESR lines are observed if an unpaired electron when closed to two non-equivalent protons is placed in magnetic field?
(A) 2
(B) 4
(C) 6
(D) 8
Answer: B

32. For which one of the following process is inter system crossing (ISC) essential?
(A) Fluorescence
(B) Radioactive decay
(C) Chemiluminescence
(D) Phosphorescence
Answer: D

33. The molecules of H2O belongs to the point group :
(A) D4
(B) C3V
(C) C2V
(D) C3
Answer: C

34. Which one of the following types of bonding is true for ferrocene?
(A) Localised Fe-C bond
(B) Delocalised Fe-C bond
(C) Ionic bond having Fe2+ (-C5H5-)2
(D) Hydrogen bridge bonding
Answer: B

35. What is the effect of hydrogen bonding on the IR absorption of N-H group?
(A) It shifts to lower wave number
(B) It shifts to higher wave number
(C) No change is observed
(D) None of these
Answer: A

36. A symmetry element which distinguishes maleic acid from fumaric acid is :
(A) C2
(B) I
(C) S4
(D) None of the above
Answer: A

37. How many hyperfine lines in ESR spectrum are shown by Mn2+?
(A) 6
(B) 5
(C) 4
(D) 3
Answer: A

38. A is the stereoisomer of the compound B, Therefore A and B differ in their :
(A) Composition
(B) Steric Hindrance
(C) Configuration
(D) Constitution
Answer: C

39. The hybridization of the central carbon in allenes is :
(A) dsp2
(B) sp3
(C) sp2
(D) sp
Answer: D

40. High quantum yields of photochemical reactions are due to :
(A) Lowering of activation energy
(B) Accompanying side reactions
(C) Formation of free radicals
(D) High frequency of collision
Answer: B

41. What is the eigen value of sin2`x` which is not an eigen function of the operator ‘d/dx’ but of ‘d2/dx2’?
(A) 2
(B) `-2`
(C) 4
(D) `-4`
Answer: D

42. In first order reaction `A_((g))` ““ `_(g)` `+C_((g))`, the initial pressure is 11200 Pa and half life period of the reaction is 29.93 min. What is the total pressure at the end of 16 minutes?
(A) 14667 Pa
(B) 15656 Pa
(C) 16235 Pa
(D) 14555 Pa
Answer: A

43. Predict the number of translational, rotational and vibrational degrees of freedom in neon :
(A) 3, 0, 1
(B) 3, 1, 0
(C) 3, 0, 0
(D) 3, 1, 1
Answer: C

44. How many diastereomers are shown by the molecules `CH3CH=CHCH=CH-C2H5?`
(A) 1
(B) 4
(C) 3
(D) 2
Answer: B

45. The term ‘quantum mechanics’ was first introduced by :
(A) Schrondinger
(B) Max Born
(C) Bohr
(D) Einstein
Answer: B

46. Which of the following radiation has the longest wavelength?
(A) UV
(B) Micro wave
(C) Cosmic wave
(D) Radio wave
Answer: D

47. Transmittance in spectroscopy analysis is a function primarily of the :
(A) Optical path
(B) Monochromator
(C) Velocity of light
(D) Barometric pressure
Answer: C

48. Which of the following properties of transition metal complexes can be explained on the basis of crystal field theory?
(A) Colour
(B) Magnetic moment
(C) Dipole moment
(D) Both (A) and (B)
Answer: D

49. Which of the following symmetry elements is not possessed by trans-dichlorobenzene?
(A) C2
(B) i
(C) S4
(D) Sh
Answer: C

50. The number of vibrational degrees of freedom in toluene is :
(A) 39
(B) 40
(C) 9
(D) 24
Answer: A