d and f Block Elements — JEE Main PYQs

${\mathrm{MnO}}_4^{2-}$, in acidic medium, disproportionates to :

Consider the following reactions:
$\mathrm{NaCl}+{\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7+{\mathrm{H}}_2{\mathrm{SO}}_4\to \mathrm{A}+{\mathrm{KHSO}}_4+{\mathrm{NaHSO}}_4+{\mathrm{H}}_2\mathrm{O}$ …

Given below are some of the statements about Mn and ${\mathrm{Mn}}_2{\mathrm{O}}_7$. Identify the correct statements
A. Mn forms the oxide ${\mathrm{Mn}}_2{\mathrm{O}}_7$ in which Mn is in its highest oxidation state.
B. Oxygen stabilizes the Mn in higher oxidation states by fo …

On heating a mixture of common salt and ${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ in equal amount along with concentrated ${\mathrm{H}}_2{\mathrm{SO}}_4$ in a test tube, a gas is evolved. Formula of the gas evolved and oxidation state of the central metal atom in the gas r …

Among the following oxides of 3d elements, the number of mixed oxides are _____. …

The oxidation state of chromium in the final product formed in the reaction between KI and acidified ${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ solution is:

"X" is an oxoanion of the lightest element of group 7 (in the periodic table). The metal is in +6 oxidation state in "X". The color of the potassium salt of X is

Given below are two statements:

Statement I: The number of pairs, from the following, in which both the ions are coloured in aqueous solution is 3.
$[\mathrm{Sc}{}^{3+},\mathrm{Ti}{}^{3+}]$, $[\mathrm{Mn}{}^{2+},\mathrm{Cr}{}^{2+}]$, $[\mathrm{Cu}{}^{2+},\mathrm{Zn}{}^{2+}]$ and $[\mathrm{Ni}{}^{2+},\mathrm{Ti}{}^{4+}]$
S …

Consider the following statements about manganate and permanganate ions. Identify the correct statements :
A. The geometry of both manganate and permanganate ions is tetrahedral.
B. The oxidation states of Mn in manganate and permanganate are +7 and +6 , respectively.
C. Oxidatio …

Which of the following sets includes all the species that will change the orange colour of ${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ in acidic medium?

In order to oxidise a mixture of 1 mole each of $\mathrm{FeC}{}_2\mathrm{O}{}_4$, $\mathrm{Fe}{}_2(\mathrm{C}{}_2\mathrm{O}{}_4){}_3$, $\mathrm{FeSO}{}_4$ and $\mathrm{Fe}{}_2(\mathrm{SO}{}_4){}_3$ in acidic medium, the number of moles of $\mathrm{KMnO}{}_4$ required is:

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 grea …

Correct statements from the following are
(A) Potassium dichromate is an oxidising agent and it oxidises $\mathrm{FeSO}{}_4$ to $\mathrm{Fe}{}_2(\mathrm{SO}{}_4){}_3$ in acidic medium.
(B) Sodium dichromate can be used as primary standard in volumetric estimation.
(C) $\mathrm{CrO}{}_4{}^{2-}$ and $\mathrm{Cr}{}_2\mathrm{O}{}_7{}^{2-}$ a …

Identify the colour of compound ' X ' in the sequence of the reaction.

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 …

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

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. Sc³⁺
B. Zn²⁺
C. V²⁺
D. Fe²⁺
E. Co²⁺

Choose the correct answer from the options given belo …

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

A paper dipped in a dil. H₂SO₄ solution of 'X' upon treatment with SO₂ gas turns into green. The compound 'X' is :

The correct statements among the following are :
A. Basic vanadium oxide is used in the manufacture of ${\mathrm{H}}_2{\mathrm{SO}}_4$.
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 meta …

Given below are two statements :

Statement I : The number of pairs among $[{\mathrm{Ti}}^{4+},{\mathrm{V}}^{2+}]$, $[{\mathrm{V}}^{2+},{\mathrm{Mn}}^{2+}]$, $[{\mathrm{Mn}}^{2+},{\mathrm{Fe}}^{3+}]$ and $[{\mathrm{V}}^{2+},{\mathrm{Cr}}^{2+}]$ in which both ions are coloured is 3.

Statemen …

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 : …

Lanthanoid ions with $4{\mathrm{f}}^7$ 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 :

Which of the following ions is the strongest oxidizing agent?
(Atomic Number of $\mathrm{Ce}=58,\mathrm{Eu}=63,\mathrm{Tb}=65,\mathrm{Lu}=71]$

Preparation of potassium permanganate from ${\mathrm{MnO}}_2$ involves two step process in which the $1^{\text{st }}$ step is a reaction with KOH and ${\mathrm{KNO}}_3$ to produce

The d-electronic configuration of an octahedral Co(II) complex having magnetic moment of 3.95 BM is:

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

The metal ion whose electronic configuration is not affected by the nature of the ligand and which gives a violet colour in non-luminous flame under hot condition in borax bead test is

Which of the following oxidation reactions are carried out by both ${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ and ${\mathrm{KMnO}}_4$ in acidic medium?
A. ${\mathrm{I}}^{-}\to {\mathrm{I}}_2$
B. ${\mathrm{S}}^{2-}\to \mathrm{S}$
C. …

Consider the following reactions


The product …

The amphoteric oxide among ${\mathrm{V}}_2{\mathrm{O}}_3,{\mathrm{V}}_2{\mathrm{O}}_4$ and ${\mathrm{V}}_2{\mathrm{O}}_5$ 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 ${\mathrm{Mn}}_2{\mathrm{O}}_3$, TiO and VO is ____ B.M. (Nearest integer).

The correct option with order of melting points of the pairs $(\mathrm{Mn},\mathrm{Fe}),(\mathrm{Tc},\mathrm{Ru})$ and $(\mathrm{Re},\mathrm{Os})$ is :

The spin-only magnetic moment value of ${\mathrm{M}}^{\mathrm{n}+}$ 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 ${\mathrm{K}}_2[{\mathrm{NiCl}}_4]$, …

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
$\mathrm{A}+\mathrm{NaCl}+{\mathrm{H}}_2{\mathrm{SO}}_4\to {\mathrm{CrO}}_2{\mathrm{Cl}}_2+$ Side Products
Little
amount …

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

Pair of transition metal ions having the same number of unpaired electrons is :

KMnO₄ acts as an oxidising agent in acidic medium. 'X' is the difference between the oxidation states of Mn in reactant and product. 'Y' is the number of 'd' electrons present in the brown red precipitate formed at the end of the acetate ion test with neutral ferric chloride. The …

The number of valence electrons present in the metal among $\mathrm{Cr},\mathrm{Co},\mathrm{Fe}$ 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 (${\mathrm{M}}^{\mathrm{n}+}$) exists in green colour. The nature of the oxide formed by the above ${\mathrm{M}}^{\mathrm{n}-}$ ion is :

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

Consider the following reaction
${\mathrm{MnO}}_2+\mathrm{KOH}+{\mathrm{O}}_2\to \mathrm{A}+{\mathrm{H}}_2\mathrm{O}$.
Product 'A' in neutral or acidic medium disproportionate to give products ' B ' and ' C ' along with water. The sum of spin-only magnetic moment value …

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 ${\mathrm{M}}_2{\mathrm{O}}_{\mathrm{n}}$ (where $\mathrm{n}=3,4,5)$. The 'spin-only' magnetic moment value of the amphoteric oxide from the …

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

In a borax bead test under hot condition, a metal salt (one from the given) is heated at point B of the flame, resulted in green colour salt bead. The spin-only magnetic moment value of the salt is
____ BM (Nearest integer)
[Given atomic number of …

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)