Chemistry Chapter 12 Entry Test MCQs
26. Transition elements are coloured:
a. Due to metallic nature
b. Due to small size
c. Due to unpaired d – electrons
d. All of these
27. Transition metals are often paramagnetic owing to
a. The presence of one or more unpaired electrons in the system
b. Their high M.P. and B.P.
c. Their being less electropositive than the elements of groups I-A and II-A
d. The presence of vacant orbitals
28. Maximum number of oxidation states of transition metal is derived from the following configuration:
a. (n + 1) d electron
b. ns electron
c. ns + (n – 1)d electron
d. (n – 1)d electron
29. Zinc does not show variable valency like d-block elements because:
a. d-orbital is complete
b. It is a soft metal
c. Two electrons are present in the outermost orbit
d. It is low melting
30. Which of the following statement is correct?
a. Iron belongs to second transition series of the periodic table
b. Iron belongs to 3rd transition series of the periodic table
c. Iron belongs to group VIII of the periodic table
d. Iron belongs to f-block of the periodic table
31. The number of unpaired electrons in ferrous ion is:
a. 3
b. 5
c. 2
d. 4
32. Fe, Co and Ni have valuable catalytic properties in process involving
a. Compounds of hydrogen
b. Organic compound
c. Oxidation
d. Hydrogenation
33. Zinc, cadmium and mercury show the properties of
a. Transitional elements
b. Typical elements
c. Rare elements
d. Normal elements
34. The hardness of Cr is due to …… and metallic lusture is due to …….
a. Covalent bond, hydrogen bond
b. Covalent bond, metallic bond
c. Metallic bond, hydrogen bond
d. Metallic bond, covalent bond
35. In the following transition elements, the lowest M.P. and B.P. is exhibited by:
a. Cu
b. Cr
c. Au
d. Hg
36. A transition element X has configuration [Ar]3d4 in its + 3 oxidation state. Its atomic number is:
a. 22
b. 25
c. 19
d. 26
37. Common oxidation state of scandium, a transition element is/are [atomic number of Sc = 21]
a. +1
b. +4
c. + 4 and +1
d. + 2 and + 3
38. The electronic configuration of cobalt is:
a. 1s2, 2s2 2p6, 3s2 3p6, 3d7, 4s2
b. 1s2, 2s2, 3s2 3p6 3d1, 4s2
c. 1s2, 2s2, 2p6, 3p6 3d5, 4s2
d. 1s2, 2s2, 3s2 2p6 3d3, 4s2
39. The elements belonging to the first transition series have atomic number from
a. 24 to 30
b. 19 to 37
c. 21 to 30
d. 22 to 32
40. Zinc and mercury do not show variable valency like d-block elements because:
a. They have only two electrons in the outermost subshell
b. They are soft
c. Their d-shells are incomplete
d. Their d- shells are complete
41. Which of the following ions has the least magnetic moment?
a. Co+3
b. Cu+2
c. Fe+2
d. Ni+2
42. Which of the following compound expected to be colourless?
a. CuCN
b. ScO
c. Cr2(SO4)3
d. V2O3
43. Electronic configuration of Zn+2 is:
a. 4s13d9
b. 4s23d8
c. 5s04d10
d. 4s03d10
44. [Sc(H2O)6]3+ ion is
a. Coloured and octahedral
b. Colourless and diamagnetic
c. Coloured and paramagnetic
d. Colourless and paramagnetic
45. The elements with atomic numbers 21 to 30 belong to
a. first transition elements
b. Halogens
c. Lanthanides
d. Noble gas
46. The outer electronic configuration of copper is
a. (3D) 10(4s)0
b. (3D) 10(4s)1
c. (3D) 10(4s)2
d. (3D) 9 (4s)2
47. Which of the following pairs show resemblance in their valence shell configuration?
a. Zn, Cd
b. Ti, Tl
c. Pt, Au
d. Mn, Zn
48. Ti3+ salts are purple coloured, what is the colour of Ti4+ salts:
a. Blue
b. Colourless
c. Green
d. Purple
49. In 3-d series which elements is usually found in +4 oxidation state:
a. Cr
b. Mn
c. V
d. Ti
50. Which of the following cation has maximum unpaired electrons?
a. Mn+2
b. Ni+2
c. Fe2+
d. Co+2