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Question Bank No: 1

1. Number of moles of $K_{2} {Cr}_{2} O_{7}$ reduced by one mole of iodode ions is

a)		3
b)		1/3
c)		6
d)		1/6

2. The electronic configuration of ${Cu}^{2 +}$ ion is

a)		[Ar]3 $d^{7} 4 s^{2}$
b)		[Ar]3 $d^{8} 4 s^{1}$
c)		[Ar]3 $d^{9} 4 s^{0}$
d)		[Ar]3 $d^{10}$

3. When manganese dioxide is fused with KOH in air, it gives

a)		Potassium permanganate
b)		Potassium manganate
c)		manganese hydroxide
d)		${Mn}_{3} O_{4}$

4. The "spin-only" magnetic moment [in units of Bohr magneton, ( $μ_{B})]$ of ${Ni}^{2 +}$ in aqueouss solution would be (At. No.Ni =28)

a)		2.84
b)		4.90
c)		0
d)		1.73

5. Heating mixture of ${Cu}_{2} O$ and ${Cu}_{2} S$ will give

a)		${Cu}_{2} S O_{3}$
b)		CuO+CuS
c)		Cu+ ${SO}_{3}$
d)		Cu+S $O_{2}$

6. The oxidation state of chromium in the final product formed by reaction between KI and acidified potassium dichromate solution is

a)		+3
b)		+2
c)		+6
d)		+4

7. Which of the following oxides is acidic in nature?

a)		$V_{2} O_{5}$
b)		MnO
c)		${Cr}_{2} O_{3}$
d)		Mn $O_{2}$

8. Which of the following species has 55 unpaired electrons?

a)		${Mn}^{2 +}$
b)		${Cr}^{2 +}$
c)		${Cr}^{3 +}$
d)		${Ti}^{3 +}$

9. Oxidation state of chromium in chromic acid is

a)		0
b)		+7
c)		+3
d)		+6

10. Which of the following would be diamagnetic?

a)		${Cu}^{2 +}$
b)		${Ni}^{2 +}$
c)		${Cd}^{2 +}$
d)		${Ti}^{3 +}$

11. Which of the following oxides is acidic in nature?

a)		NiO
b)		ZnO
c)		CoO
d)		FeO

12. When KMn $O_{4}$ acts as oxidising agent in acidic medium, the oxidation number of Mn decreases by

a)		1
b)		2
c)		10
d)		5

13. In the first transition series, the element with lowest melting point belong to group

a)		3
b)		4
c)		10
d)		12

14. Among transition elements the element with lowest melting point belongs to group

a)		3
b)		11
c)		6
d)		12

15. The number of moles of KMn $O_{4}$ that will be needed to react with one mole of sulphate ion in acidic solution is

a)		2/5
b)		3/5
c)		4/5
d)		1

16. In the first transition series, the element with highest melting point is

a)		Mn
b)		Fe
c)		Cr
d)		Cu

17. Copper displaces the metal in the salt solution of

a)		AgN $O_{3}$
b)		ZnS $O_{4}$
c)		FeS $O_{4}$
d)		NiS $O_{4}$

18. When Mn $O_{2}$ is fused with KOH in air, it gives

a)		KMn $O_{4}$
b)		M $n_{3} O_{4}$
c)		$K_{2} Mn O_{4}$
d)		Mn $(OH)_{2}$

19. Coinage metals are present in

a)		S-block
b)		d-block
c)		p-block
d)		f-block

20. When ${SO}_{2}$ is passed through acidified $K_{2} {Cr}_{2} O_{7}$ solution

a)		The solution turns blue
b)		The solution is decolourised
c)		${SO}_{2}$ is reduced
d)		green ${Cr}_{2} ({SO}_{4})_{3}$ is formed

21. Which pair of the following chlorides do not impart colour to the flame?

a)		${BeCl}_{2}$ and ${SrCl}_{2}$
b)		${BeCl}_{2}$ and ${MgCl}_{2}$
c)		${CaCl}_{2}$ and ${BaCl}_{2}$
d)		${BaCl}_{2}$ and ${SrCl}_{2}$

22. The primary and secondary valencies of chromium in the complex ion, dichlorodioxalatochromium (111) are respectively

a)		3,4
b)		4,3
c)		3,6
d)		6,3

23. Which of the following d-block elements has half-filled penultimate d-subshell as well as half filled valence s-subshell?

a)		Cr
b)		Pd
c)		Pt
d)		Cu

24. Which of the following pairs of transition metal ions are the stronger oxidizing agents in aqueous solutions?

a)		$V^{2 +}$ and ${Cr}^{2 +}$
b)		${Ti}^{2 +}$ and ${Cr}^{2 +}$
c)		${Mn}^{3 +}$ and ${Co}^{3 +}$
d)		$V^{2 +}$ and ${Fe}^{2 +}$

25. Among the following complexes which has a magnetic moment of 5.9 BM?
$Ni {(CO)}_{4}, [Fe {(H_{2} O)}_{6}]^{2 +}, [CO {({NH}_{2})}_{6}]^{3 +}, [Mn {Br}_{4}]^{2 -}$

a)		$Ni {(CO)}_{4}$
b)		$[Fe {(H_{2} O)}_{6}]^{2 +}$
c)		$[CO {({NH}_{2})}_{6}]^{3 +}$
d)		$[Mn {Br}_{4}]^{2 -}$

26. The following is known as "Bordeaux mixture"

a)		Borax and copper sulphate
b)		Orthoboric acid and ferrous sulphate
c)		Sodium borate and zinc sulphate
d)		Copper sulphate and lime

27. Among the following transition elements pick out the element / elements with highest secondionization energy

a)		V(At. no = 23)
b)		Cr(At. no =24)
c)		Mn (At. no =25)
d)		Cu (At. no =29)

28. The correct order of the number of unpaired electrons in the ions. ${Cu}^{2 +}, {Ni}^{2 +}, {Fe}^{3 +}$ and ${Cr}^{3 +}$ is

a)		${Cu}^{2 +} > {Ni}^{2 +} > {{Cr}^{3 +} > Fe}^{3 +}$
b)		${{Cr}^{3 +} > Fe}^{3 +} > {Ni}^{2 +}$ $>$ ${Cu}^{2 +}$
c)		${Fe}^{3 +} > {Cr}^{3 +} > {Cu}^{2 +} > {Ni}^{2 +}$
d)		${Fe}^{3 +} > {Cr}^{3 +} > {Ni}^{2 +} > {Cu}^{2 +}$

29. The pair of $[Co ({SO}_{4}) ({NH}_{3})_{5}] Cl$ and $[Co Cl ({NH}_{3})_{5}] {SO}_{4}$ constitutes

a)		Optical isomers
b)		Linkage isomers
c)		Co-ordination isomers
d)		Ionisation isomers

30. Which one of the following pairs of elements is called 'chemical twins' because of their very similar chemical properties?

a)		Mn and W
b)		Mb and Tc
c)		Hf and Zr
d)		Fe and Co

31. When one mole of each of the following complex salts is treated with excess of Ag ${NO}_{3},$ which of them gives maximum amount of AgCl?

a)		$[Co ({NH}_{3})_{6}] {Cl}_{3}$
b)		$[Co ({NH}_{3})_{5} Cl] {Cl}_{2}$
c)		$[Co ({NH}_{3})_{4} {Cl}_{2}] Cl$
d)		${Na}_{2} [PtC l_{6}]$

32. Which of the following species is expected to show the highest magnetic moment?
(Atomic numbers :Cr=24: Mn=25:Co=27:Ni=28:Cu=29)

a)		${Cr}^{2 +}$
b)		${Mn}^{2 +}$
c)		${Cu}^{2 +}$
d)		${CO}^{2 +}$

33. The lanthanide contraction relates to

a)		Atomic radii
b)		Atomic as well as $M^{3 +} radii$
c)		Valence electrons
d)		Oxidation states

34. In the brown ring test for the nitrate ion, the brown colour is due to

a)		${[Fe {(H_{2} O)}_{5} NO]}^{2 +}$
b)		${[Fe {(H_{2} O)}_{5} NO]}^{3 +}$
c)		${[Fe {(H_{2} O)}_{5}]}^{+}$
d)		${[Fe {(H_{2} O)}_{5} {NO}_{2}]}^{2 +}$

35. Guignet's green is known as

a)		${Cr}_{2} O_{3} {2 H}_{2} O$
b)		${FeO}_{3} {2 H}_{2} O$
c)		${FeCO}_{3} {Cr}_{2} O_{3}$
d)		${FeO . Cr}_{2} O_{3}$

36. The magnetic moment $μ,$ of transition metals is related to the number of unpaired electrons n as

a)		$μ = n {(n + 2)}^{2}$
b)		$μ = n^{2} (n + 2)$
c)		$μ = n / \sqrt{(n + 2)}$
d)		$μ = \sqrt{n (n + 2)}$

37. Lanthanide contraction is due to increase in

a)		Shielding by 4f electrons
b)		atomic number
c)		effective nuclear charge
d)		size of 4f orbital

38. All the following statements about the transitional elements are true except that

a)		All of the transitional elements are predominantly metallic
b)		In aqueous solution many of their simple ions are coloured
c)		Most of the transitional elements show pronounced catalytic activity
d)		Most of the transitional elements show only only one valence state