The d- and f- Block Elements Test

Directions For Questions

Two types of magnetic behaviour are found in substances :
(a) Diamagnetism and (b) Paramagnetism
Diamagnetic substances are those which are repelled by an applied magnetic field. Such substances have no unpaired electron. Paramagnetic substances are those which are attracted by an applied magnetic field. Transition metals and many of their compounds show paramagnetic behaviour where there are unpaired electron or electrons. The magnetic moment arise from the spin and orbital motions in ions or molecules. Magnetic moment of

n

unpaired electrons is given as,

\mu =\sqrt { n\left( n+2 \right)  }

Bor Magneton

Magnetic moment increases as the number of unpaired electrons increases.

...view full instructions

Arrange the following in increasing value of magnetic moments.
(i) $[Fe(CN)_6]^{4-}$
(ii) $Fe(CN)_6]^{3-}$
(iii) $Cr(NH_3)_6^{ 3+}$
(iv) $Ni(H_2O)^4]^{ 2+}$

	Column I		Column II
(A)	$FeSO_4.7H_2O$	(i)	Green
(B)	$NiCl_2.4H_2O$	(ii)	Light Pink
(C)	$MNCl_2.4H_2O$	(iii)	Pale green
(D)	$CoCl_2.6H_20$	(iv)	Pink
(E)	$Cu_2Cl_2$	(v)	Colourless

The d- and f- B...

Question 1

diagonal relationship.

lanthanoid contraction.

actinoid contraction.

belonging to the same group.

Question 2

Atomic radii

Ionisation energies

Magnetic moments

Lattice energies

Question 3

2.87 B.M.

3.87 B.M.

3.47 B.M.

3.57 B.M.

Question 4

lanthanoid contraction which results in almost same radii of second and third row metals

diagonal relationship between second and third row elements

similar ionisation enthalpy of second and third row elements

similar oxidation states of second and third row metals

Question 5

Diamagnetic substances are repelled by an applied magnetic field.

Paramagnetic substances are attracted by an applied magnetic field.

Magnetic moment of n unpaired electrons is given by μ=n(n−2)\mu=\sqrt n(n-2)μ=n​(n−2)B.M.

Magnetic moment increases as the number of unpaired electrons increases.

Question 6

[Ti(H2O)6]3+[Ti(H_2O)_6]^{3+}[Ti(H2​O)6​]3+

[Cu(NH3)4]2+[Cu(NH_3)_4]^{2+}[Cu(NH3​)4​]2+

[CoF6]3−[CoF_6]^{3-}[CoF6​]3−

CrO42−CrO_4^{2-}CrO42−​

Question 7

(I)<(II)<(III)<(IV)(I) < (II) < (III) < (IV)(I)<(II)<(III)<(IV)

(I)<(II)<(IV)<(III)(I) < (II) < (IV) < (III)(I)<(II)<(IV)<(III)

(II)<(III)<(I)<(IV)(II) < (III) < (I) < (IV)(II)<(III)<(I)<(IV)

(IV)<(III)<(II)<(I)(IV) < (III) < (II) < (I)(IV)<(III)<(II)<(I)

Question 8

It is a redox reaction in which green solution of [Cr(H2O)6]+3[Cr(H_2O)_6]^{+3}[Cr(H2​O)6​]+3 is produced.

One of the product is reaction has trigonal planar structure.

Dimeric bridged tetrahedral metal ion is produced.

Dark blue color in obtained in reaction.

Question 9

(A) - (iii), (B) - (iv), (C) - (i), (D) - (ii), (E) - (v)

(A) - (ii), (B) - (iii), (C) - (iv), (D) - (i), (E) - (v)

(A) - (v), (B) - (ii), (C)-(iii), (D) - (iv), (E) - (i)

(A) - (iii), (B)-(i), (C)-(ii), (D) - (iv), (E).- (v)

Question 10

Cu3+Cu^{3+}Cu3+< Fe3+Fe^{3+}Fe3+ <Cr3+Cr^{3+}Cr3+<Sc3+Sc^{3+}Sc3+: stability in aqueous solution

V2+V^{2+}V2+< Cr2+Cr^{2+} Cr2+<Fe2+Fe^{2+}Fe2+<Mn2+Mn^{2+} Mn2+: paramagnetic behaviour

Ni2+Ni^{2+}Ni2+< Co2+Co^{2+}Co2+ <Fe2+Fe^{2+}Fe2+ <Mn2+Mn^{2+}Mn2+: ionic size

Co3+Co^{3+}Co3+< Fe3+Fe^{3+}Fe3+ <Cr3+Cr^{3+}Cr3+<Sc3+Sc^{3+}Sc3+: stability in aqueous solution

User

Question Analysis

Results Announcement on: coming Monday

Stay Tuned: We’ll update you on your result via email or SMS.

Magnetic moment of n unpaired electrons is given by $\mu=\sqrt n(n-2)$ B.M.

$[Ti(H_2O)_6]^{3+}$

$[Cu(NH_3)_4]^{2+}$

$[CoF_6]^{3-}$

$CrO_4^{2-}$

$(I) < (II) < (III) < (IV)$

$(I) < (II) < (IV) < (III)$

$(II) < (III) < (I) < (IV)$

$(IV) < (III) < (II) < (I)$

It is a redox reaction in which green solution of $[Cr(H_2O)_6]^{+3}$ is produced.

$Cu^{3+}$ < $Fe^{3+}$ < $Cr^{3+}$ < $Sc^{3+}$ : stability in aqueous solution

$V^{2+}$ < $Cr^{2+}$ < $Fe^{2+}$ < $Mn^{2+}$ : paramagnetic behaviour

$Ni^{2+}$ < $Co^{2+}$ < $Fe^{2+}$ < $Mn^{2+}$ : ionic size

$Co^{3+}$ < $Fe^{3+}$ < $Cr^{3+}$ < $Sc^{3+}$ : stability in aqueous solution