d- and f-Block Elements — JEE Main PYQs

Given below are two statements :

Statement I : Among Zn, Mn, Sc and Cu, the energy required to remove the third valence electron is highest for Zn and lowest for Sc.

Statement II : The correct order of the following complexes in terms of CFSE is $\mathrm{[Co(H_2O)_6]^{2+}} < \mathrm{[Co(H_2O)_6]^{3+}} < \mathrm{[Co(en)_3]^{3+}}$.

In the light of the above statements, choose the correct answer from the options given below :

Among $\mathrm{Fe^{2+}}$, $\mathrm{Fe^{3+}}$, $\mathrm{Cr^{2+}}$ and $\mathrm{Zn^{2+}}$, the ion that shows positive borax bead test and with highest ionisation enthalpy is :

Number of paramagnetic ions among the following d- and f-block metal ions is __________.

$\mathrm{Mn^{2+}}$, $\mathrm{Cu^{2+}}$, $\mathrm{Zn^{2+}}$, $\mathrm{Yb^{2+}}$, $\mathrm{Sc^{3+}}$, $\mathrm{La^{3+}}$, $\mathrm{Gd^{3+}}$, $\mathrm{Lu^{3+}}$, $\mathrm{Ti^{4+}}$, $\mathrm{Ce^{4+}}$

(Atomic number of Mn = 25, Cu = 29, Zn = 30, Yb = 70, Sc = 21, La = 57, Gd = 64, Lu = 71, Ti = 22, Ce = 58)

The correct statements among the following are,

A. Mo(VI) and W(VI) are less stable than Cr(VI). B. $\mathrm{Ce^{4+}}$ and $\mathrm{Tb^{4+}}$ are oxidant while $\mathrm{Eu^{2+}}$ and $\mathrm{Yb^{2+}}$ are reductant. C. Cm and Am have seven unpaired electrons. D. Actinoid contraction is greater from element to element than lanthanoid contraction.

Choose the correct answer from the options given below:

Correct statements from the following are

A. Potassium dichromate is an oxidising agent and it oxidises $\mathrm{FeSO_4}$ to $\mathrm{Fe_2(SO_4)_3}$ in acidic medium. B. Sodium dichromate can be used as primary standard in volumetric estimation. C. $\mathrm{CrO_4^{2-}}$ and $\mathrm{Cr_2O_7^{2-}}$ are interconvertible in aqueous solution by varying the pH of the solution. D. Cr-O-Cr bond angle in $\mathrm{Cr_2O_7^{2-}}$ is $126°$.

Choose the correct answer from the options given below:

Pairs of elements with the same number of electrons in their respective 4f orbital are

[Atomic number: Eu-63, Gd-64, Dy-66, Ho-67, Tm-69, Yb-70, Lu-71, Hf-72]

A. (Eu and Gd)

B. (Dy and Ho)

C. (Yb and Hf)

D. (Lu and Tm)

Choose the correct answer from the options given below:

Consider $|x|$ is the difference in oxidation states of Mn in highest manganese fluoride and highest manganese oxide. The ions with $|x|$ number of unpaired electrons from the following are:

A. $\mathrm{Sc^{3+}}$

B. $\mathrm{Zn^{2+}}$

C. $\mathrm{V^{2+}}$

D. $\mathrm{Fe^{2+}}$

E. $\mathrm{Co^{2+}}$

Choose the correct answer from the options given below:

Which of the following is NOT a physical or chemical characteristics of interstitial compounds?

Given below are two statements :

Statement I : Presence of large number of unpaired electrons in transition metal atoms results in higher enthalpies of their atomisation.

Statement II : $d_{xy} = d_{xz} = d_{yz} < d_{x^2-y^2} = d_{z^2}$ and $d_{x^2-y^2} = d_{z^2} < d_{xy} = d_{xz} = d_{yz}$ are the d-orbital splittings in $\mathrm{[Fe(H_2O)_6]^{3+}}$ and $\mathrm{[Ni(Cl)_4]^{2-}}$ complex ions respectively.

In the light of the above statements, choose the correct answer from the options given below :

The correct statements among the following are.

A. Basic vanadium oxide is used in the manufacture of $\mathrm{H_2SO_4}$. B. The spin-only magnetic moment value of the transition metal halide employed in Ziegler-Natta polymerization is 2.84 BM. C. The p-block metal compound employed in Ziegler-Natta polymerization has the metal in +3 oxidation state. D. The number of electrons present in the outer most 'd' orbital of metal halide employed in Wacker process is 8.

Choose the correct answer from the options given below:

The correct order of first ($\Delta_i H_1$) and second ($\Delta_i H_2$) ionisation enthalpy values of Cr and Mn are :

A. $\Delta_i H_1$ : Cr > Mn

B. $\Delta_i H_2$ : Cr > Mn

C. $\Delta_i H_1$ : Mn > Cr

D. $\Delta_i H_2$ : Mn > Cr

Choose the correct answer from the options given below :

Given below are two statements :

Statement I : The number of pairs among $\mathrm{[Ti^{1+}, V^{2+}]}$, $\mathrm{[V^{2+}, Mn^{2+}]}$, $\mathrm{[Mn^{2+}, Fe^{3+}]}$ and $\mathrm{[V^{2+}, Cr^{2+}]}$ in which both ions are coloured is 3.

Statement II : The number of pairs among $\mathrm{[La^{3+}, Yb^{2+}]}$, $\mathrm{[Lu^{3+}, Ce^{4+}]}$ and $\mathrm{[Ac^{3+}, Lr^{3+}]}$ ions in which both are diamagnetic is 3.

In the light of the above statements, choose the correct from the options given below :

Given below are two statements for catalytic properties of transition metals.

Statement I : First row transition metals which act as catalyst utilise their 3d electrons only for formation of bonds between reactant molecules and atoms on the surface of catalyst.

Statement II : There is increase in the concentration of reactants on the surface of catalyst which strengthens the bonds in reacting molecules.

In the light of the above statements, choose the correct answer from the options given below :

The spin-only magnetic moment value of $\mathrm{M^{n+}}$ ion formed among Ni, Zn, Mn and Cu that has the least enthalpy of atomisation is __________. (in nearest integer)

Here n is equal to the number of diamagnetic complexes among $\mathrm{K_2[NiCl_4]}$, $\mathrm{[Zn(H_2O)_6]Cl_2}$, $\mathrm{K_3[Mn(CN)_6]}$ and $\mathrm{[Cu(PPh_3)_3I]}$

The metal ions that have the calculated spin-only magnetic moment value of 4.9 B.M. are :

A. $\mathrm{Cr^{2+}}$ B. $\mathrm{Fe^{2+}}$ C. $\mathrm{Fe^{3+}}$ D. $\mathrm{Co^{2+}}$ E. $\mathrm{Mn^{3+}}$

Choose the correct answer from the options given below:

Consider the following reactions

$\underset{\text{Little amount}}{\mathrm{A}} + \mathrm{NaCl} + \mathrm{H_2SO_4} \rightarrow \mathrm{CrO_2Cl_2} + \text{Side Products}$

$\mathrm{CrO_2Cl_2}_{\,\text{(Vapour)}} + \mathrm{NaOH} \rightarrow \mathrm{B} + \mathrm{NaCl} + \mathrm{H_2O}$

$\mathrm{B} + \mathrm{H^+} \rightarrow \mathrm{C} + \mathrm{H_2O}$

The number of terminal 'O' present in the compound 'C' is __________.

Given below are two statements:

Statement I : $\mathrm{CrO_3}$ is a stronger oxidizing agent than $\mathrm{MoO_3}$

Statement II : Cr(VI) is more stable than Mo(VI)

In the light of the above statements, choose the correct answer from the options given below

Among, Sc, Mn, Co and Cu, identify the element with highest enthalpy of atomisation. The spin only magnetic moment value of that element in its +2 oxidation state is __________ BM (in nearest integer).

The incorrect relationship in the following pairs in relation to ionisation enthalpies is :

The number of valence electrons present in the metal among Cr, Co, Fe and Ni which has the lowest enthalpy of atomisation is

The first transition series metal 'M' has the highest enthalpy of atomisation in its series. One of its aquated ion ($\mathrm{M^{n+}}$) exists in green colour. The nature of the oxide formed by the above $\mathrm{M^{n+}}$ ion is:

The correct decreasing order of spin only magnetic moment values (BM) of $\mathrm{Cu^+}$, $\mathrm{Cu^{2+}}$, $\mathrm{Cr^{2+}}$ and $\mathrm{Cr^{3+}}$ ions is :

Lanthanoid ions with $4f^7$ configuration are :

(A) $\mathrm{Eu^{2+}}$ (B) $\mathrm{Gd^{3+}}$ (C) $\mathrm{Eu^{3+}}$ (D) $\mathrm{Tb^{3+}}$ (E) $\mathrm{Sm^{2+}}$

Choose the correct answer from the options given below :

The number of electrons present in the $4d$ orbitals of Niobium (Nb) and Ruthenium (Ru) are "$x$" and "$y$" respectively. The value of $x + y$ is __________.

The correct set of ions (aqueous solution) with same colour from the following is:

Consider the following reactions

$$\mathrm{K_2Cr_2O_7} \xrightarrow[-H_2O]{\text{KOH}} [A] \xrightarrow[-H_2O]{\text{H}_2\text{SO}_4} [B] + \mathrm{K_2SO_4}$$

The products [A] and [B], respectively are :

Match List-I with List-II.

	List-I		List-II
(A)	Bronze	(I)	Cu, Ni
(B)	Brass	(II)	Fe, Cr, Ni, C
(C)	UK silver coin	(III)	Cu, Zn
(D)	Stainless steel	(IV)	Cu, Sn

Choose the correct answer from the options given below :

Which of the following ions is the strongest oxidizing agent? (Atomic Number of Ce = 58, Eu = 63, Tb = 65, Lu = 71)

Preparation of potassium permanganate from $\mathrm{MnO_2}$ involves two step process in which the 1st step is a reaction with KOH and $\mathrm{KNO_3}$ to produce

Match List - I with List - II.

List - I (Transition metal ion)	List - II (Spin only magnetic moment (B.M.))
(A) $\mathrm{Ti^{3+}}$	(I) 3.87
(B) $\mathrm{V^{2+}}$	(II) 0.00
(C) $\mathrm{Ni^{2+}}$	(III) 1.73
(D) $\mathrm{Sc^{3+}}$	(IV) 2.84

Choose the correct answer from the options given below :

Which of the following oxidation reactions are carried out by both $\mathrm{K_2Cr_2O_7}$ and $\mathrm{KMnO_4}$ in acidic medium?

A. $\mathrm{I^- \to I_2}$

B. $\mathrm{S^{2-} \to S}$

C. $\mathrm{Fe^{2+} \to Fe^{3+}}$

D. $\mathrm{I^- \to IO_3^-}$

E. $\mathrm{S_2O_3^{2-} \to SO_4^{2-}}$

Choose the correct answer from the options given below:

Consider 'n' is the number of lone pair of electrons present in the equatorial position of the most stable structure of $\mathrm{ClF_3}$. The ions from the following with 'n' number of unpaired electrons are

A. $\mathrm{V^{3+}}$

B. $\mathrm{Ti^{3+}}$

C. $\mathrm{Cu^{2+}}$

D. $\mathrm{Ni^{2+}}$

E. $\mathrm{Ti^{2+}}$

Choose the correct answer from the options given below:

[Stem unrecoverable: the PDF page carrying this question's stem is corrupted in both the English and Hindi copies. The visible options are transition-metal ions; the first two options are images that are also unrecoverable.]

The amphoteric oxide among $\mathrm{V_2O_3}$, $\mathrm{V_2O_4}$ and $\mathrm{V_2O_5}$, upon reaction with alkali leads to formation of an oxide anion. The oxidation state of V in the oxide anion is :

The spin only magnetic moment ($\mu$) value (B.M.) of the compound with strongest oxidising power among $\mathrm{Mn_2O_3}$, $\mathrm{TiO}$ and $\mathrm{VO}$ is __________ B.M. (Nearest integer).

The element which shows only one oxidation state other than its elemental form is :

Consider the following reaction

$$\mathrm{MnO_2 + KOH + O_2 \rightarrow A + H_2O.}$$

Product 'A' in neutral or acidic medium disproportionate to give products 'B' and 'C' along with water. The sum of spin-only magnetic moment values of B and C is ________ BM. (nearest integer) (Given atomic number of Mn is 25)

A first row transition metal in its +2 oxidation state has a spin-only magnetic moment value of 3.86 BM. The atomic number of the metal is

A first row transition metal with highest enthalpy of atomisation, upon reaction with oxygen at high temperature forms oxides of formula $\mathrm{M_2O_n}$ (where n = 3, 4, 5). The 'spin-only' magnetic moment value of the amphoteric oxide from the above oxides is ________ BM (near integer)

(Given atomic number : Sc : 21, Ti : 22, V : 23, Cr : 24, Mn : 25, Fe : 26, Co : 27, Ni : 28, Cu : 29, Zn : 30)

The metal that shows highest and maximum number of oxidation state is :

The spin-only magnetic moment value of the ion among $\mathrm{Ti^{2+}}$, $\mathrm{V^{2+}}$, $\mathrm{Co^{3+}}$ and $\mathrm{Cr^{2+}}$, that acts as strong oxidising agent in aqueous solution is ________ BM (Near integer).

(Given atomic numbers : Ti : 22, V : 23, Cr : 24, Co : 27)

The number of ions from the following that have the ability to liberate hydrogen from a dilute acid is ________.

$\mathrm{Ti^{2+}}$, $\mathrm{Cr^{2+}}$ and $\mathrm{V^{2+}}$

The fusion of chromite ore with sodium carbonate in the presence of air leads to the formation of products A and B along with the evolution of $\mathrm{CO_2}$. The sum of spin-only magnetic moment values of A and B is ________ B.M. (Nearest integer)

[Given atomic number : C : 6, Na : 11, O : 8, Fe : 26, Cr : 24]

The number of element from the following that do not belong to lanthanoids is

Eu, Cm, Er, Tb, Yb and Lu

Among $\mathrm{CrO}$, $\mathrm{Cr_2O_3}$ and $\mathrm{CrO_3}$, the sum of spin-only magnetic moment values of basic and amphoteric oxides is _______ $10^{-2}$ BM (nearest integer).

(Given atomic number of Cr is 24)

The difference in the 'spin-only' magnetic moment values of $\mathrm{KMnO_4}$ and the manganese product formed during titration of $\mathrm{KMnO_4}$ against oxalic acid in acidic medium is ________ BM. (nearest integer)

Arrange the following elements in the increasing order of number of unpaired electrons in it. (A) Sc (B) Cr (C) V (D) Ti (E) Mn

Choose the correct answer from the options given below :

Among $\mathrm{VO_2^{+}}$, $\mathrm{MnO_4^{-}}$ and $\mathrm{Cr_2O_7^{2-}}$, the spin-only magnetic moment value of the species with least oxidising ability is ________ BM (Nearest integer).

(Given atomic member V $= 23$, Mn $= 25$, Cr $= 24$)

The 'spin only' magnetic moment value of $\mathrm{MO_4^{2-}}$ is __________ BM. (Where M is a metal having least metallic radii. among Sc, Ti, V, Cr, Mn and Zn).

(Given atomic number: Sc = 21, Ti = 22, V = 23, Cr = 24, Mn = 25 and Zn = 30)

The equilibrium $\mathrm{Cr_2O_7^{2-}} \rightleftharpoons 2\mathrm{CrO_4^{2-}}$ is shifted to the right in :

Given below are two statements :

Statement (I) : Fusion of $\mathrm{MnO_2}$ with KOH and an oxidising agent gives dark green $\mathrm{K_2MnO_4}$.

Statement (II) : Manganate ion on electrolytic oxidation in alkaline medium gives permanganate ion.

In the light of the above statements, choose the correct answer from the options given below :

The electronic configuration of Cu(II) is $\mathrm{3d^9}$ whereas that of Cu(I) is $\mathrm{3d^{10}}$. Which of the following is correct ?

Number of colourless lanthanoid ions among the following is ________. $$\mathrm{Eu^{3+},\ Lu^{3+},\ Nd^{3+},\ La^{3+},\ Sm^{3+}}$$

The electronic configuration of Einsteinium is :

(Given atomic number of Einsteinium = 99)

Give below are two statements :

Statement I : The higher oxidation states are more stable down the group among transition elements unlike p-block elements.

Statement II : Copper can not liberate hydrogen from weak acids.

In the light of the above statements, choose the correct answer from the options given below :

A transition metal 'M' among Sc, Ti, V, Cr, Mn and Fe has the highest second ionisation enthalpy. The spin-only magnetic moment value of $\mathrm{M^{+}}$ ion is ________ BM (Near integer)

(Given atomic number Sc : 21, Ti : 22, V : 23, Cr : 24, Mn : 25, Fe : 26)

The transition metal having highest $3^{\text{rd}}$ ionisation enthalpy is :

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A) : In aqueous solutions $\mathrm{Cr^{2+}}$ is reducing while $\mathrm{Mn^{3+}}$ is oxidising in nature.

Reason (R) : Extra stability to half filled electronic configuration is observed than incompletely filled electronic configuration.

In the light of the above statements, choose the most appropriate answer from the options given below :

Which of the following compounds show colour due to d-d transition ?

Which of the following electronic configuration would be associated with the highest magnetic moment ?

The electronic configuration for Neodymium is :

[Atomic Number for Neodymium 60]

$\mathrm{KMnO_4}$ decomposes on heating at 513K to form $\mathrm{O_2}$ along with

In alkaline medium, $\mathrm{MnO_4^-}$ oxidises $\mathrm{I^-}$ to

Match List - I with List - II.

List - I (Species)	List - II (Electronic distribution)
(A) $\mathrm{Cr^{+2}}$	(I) $\mathrm{3d^8}$
(B) $\mathrm{Mn^{+}}$	(II) $\mathrm{3d^3 4s^1}$
(C) $\mathrm{Ni^{+2}}$	(III) $\mathrm{3d^4}$
(D) $\mathrm{V^{+}}$	(IV) $\mathrm{3d^5 4s^1}$

Choose the correct answer from the options given below :

Diamagnetic Lanthanoid ions are :

Alkaline oxidative fusion of $\mathrm{MnO_2}$ gives "A" which on electrolytic oxidation in alkaline solution produces B. A and B respectively are

The orange colour of $\mathrm{K_2Cr_2O_7}$ and purple colour of $\mathrm{KMnO_4}$ is due to

A and B formed in the following reactions are:

$$\mathrm{CrO_2Cl_2 + 4NaOH \rightarrow A + 2NaCl + 2H_2O}$$ $$\mathrm{A + 2HCl + 2H_2O_2 \rightarrow B + 3H_2O}$$

Identify correct statements from below:

A. The chromate ion is square planar. B. Dichromates are generally prepared from chromates. C. The green manganate ion is diamagnetic. D. Dark green coloured $\mathrm{K_2MnO_4}$ disproportionates in a neutral or acidic medium to give permanganate. E. With increasing oxidation number of transition metal, ionic character of the oxides decreases.

Choose the correct answer from the options given below:

The metals that are employed in the battery industries are

A. Fe B. Mn C. Ni D. Cr E. Cd

Choose the correct answer from the options given below:

Choose the correct statements from the following

A. $\mathrm{Mn_2O_7}$ is an oil at room temperature B. $\mathrm{V_2O_4}$ reacts with acid to give $\mathrm{VO_2^{2+}}$ C. $\mathrm{CrO}$ is a basic oxide D. $\mathrm{V_2O_5}$ does not react with acid

Choose the correct answer from the options given below :

In the reaction of potassium dichromate, potassium chloride and sulfuric acid (conc.), the oxidation state of the chromium in the product is (+)________.