d and f Block Elements — JEE Main PYQs

Potassium dichromate acts as a strong oxidizing agent in acidic solution. During this process, the oxidation state changes from

The set of correct statements is:
(i) Manganese exhibits +7 oxidation state in its oxide.
(ii) Ruthenium and Osmium exhibit +8 oxidation in their oxides.
(iii) Sc shows +4 oxidation state which is oxidizing in nature.
(iv) Cr shows oxidising nature in +6 oxidation state.

A solution of ${\mathrm{CrO}}_5$ in amyl alcohol has a....colour

The number of electrons involved in the reduction of permanganate to manganese dioxide in acidic medium is ______.

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : ${\mathrm{Cu}}^{2+}$ in water is more stable than ${\mathrm{Cu}}^{+}$.
Reason (R) : Enthalpy of hydration for ${\mathrm{Cu}}^{2+}$ is much less than that of …

Which of the following elements have half-filled f-orbitals in their ground state ?
(Given : atomic number
$\mathrm{Sm}=62;\mathrm{Eu}=63;\mathrm{Tb}=65;\mathrm{Gd}=64,\mathrm{Pm}=61$ )
A. Sm
B. Eu
C. Tb
D. Gd
E. Pm

Choose the correct answer from the options given below:

${\mathrm{KMnO}}_4$ oxidises ${\mathrm{I}}^{-}$ in acidic and neutral/faintly alkaline solution, respectively to

${\mathrm{Nd}}^{2+}=$ ____

The correct order of basicity of oxides of vanadium is

Which of the following 3d-metal ion will give the lowest enthalpy of hydration ( ${\Delta }_{\text{hyd }}\mathrm{H}$ ) when dissolved in water?

The disproportionation of ${\text{MnO}}_4^{2-}$ in acidic medium resulted in the formation of two manganese compounds A and B. If the oxidation state of Mn in B is smaller than that of A, then the spin-only magnetic moment ($\mu$) value of B in BM is $\_\_\_\_$. (Nearest integer)

Which of the following pair is not isoelectronic species?
(At. no. Sm, 62; Er, 68: Yb, 70: Lu, 71; Eu, 63: Tb, 65; Tm, 69)

Given below are two statements:

Statement I: Iron (III) catalyst, acidified $\mathrm{K}{}_2\mathrm{Cr}{}_2\mathrm{O}{}_7$ and neutral $\mathrm{KMnO}{}_4$ have the ability to oxidise $\mathrm{I}{}^{-}$ to $\mathrm{I}{}_2$ independently.
Statement II: Manganate ion is paramagnetic in nature and involves …

The total number of $\mathrm{Mn}=\mathrm{O}$ bonds in $\mathrm{Mn}{}_2\mathrm{O}{}_7$ is

Among ${\mathrm{Co}}^{3+}$, ${\mathrm{Ti}}^{2+}$, ${\mathrm{V}}^{2+}$ and ${\mathrm{Cr}}^{2+}$ ions, one if used as a reagent cannot liberate ${\mathrm{H}}_2$ from dilute mineral acid solution, its spin-only magnetic moment in gaseous state is _____ B.M. (Nearest integer)

The spin-only magnetic moment value of the compound with strongest oxidizing ability among $\mathrm{MnF}{}_4$, $\mathrm{MnF}{}_3$ and $\mathrm{MnF}{}_2$ is ____ B.M. [nearest integer]

In neutral or alkaline solution, ${\mathrm{MnO}}_4^{-}$ oxidises thiosulphate to:

The oxidation state of manganese in the product obtained in a reaction of potassium permanganate and hydrogen peroxide in basic medium is ____.

The spin only magnetic moment of the complex present in Fehling's reagent is ____ B.M. (Nearest integer).

The spin-only magnetic moment value of ${\mathrm{M}}^{3+}$ ion (in gaseous state) from the pairs ${\mathrm{Cr}}^{3+}/{\mathrm{Cr}}^{2+}$, ${\mathrm{Mn}}^{3+}/{\mathrm{Mn}}^2$, ${\mathrm{Fe}}^{3+}/{\mathrm{Fe}}^{2+}$ and ${\mathrm{Co}}^{3+}/{\mathrm{Co}}^{2+}$ that has negative …

The dark purple colour of KMnO₄ disappears in the titration with oxalic acid in acidic medium.
The overall change in the oxidation number of manganese in the reaction is:

The $f$ orbitals are half and completely filled, respectively in lanthanide ions
(Given: Atomic no. Eu, 63; Sm, 62; Tm, 69; Tb, 65; Yb, 70; Dy, 66)

Which one of the lanthanoids given below is the most stable in divalent form?

The most common oxidation state of Lanthanoid elements is +3. Which of the following is likely to deviate easily from +3 oxidation state?

The number of terminal oxygen atoms present in the product B obtained from the following reaction is ______.
${\mathrm{FeCr}}_2{\mathrm{O}}_4+{\mathrm{Na}}_2{\mathrm{CO}}_3+{\mathrm{O}}_2\to \mathrm{A}+{\mathrm{Fe}}_2{\mathrm{O}}_3+{\mathrm{CO}}_2$ …

An acidified manganate solution undergoes disproportionation reaction. The spin-only magnetic moment value of the product having manganese in higher oxidation state is ____
B.M. (Nearest integer)

The spin-only magnetic moment value of the most basic oxide of vanadium among ${\mathrm{V}}_2{\mathrm{O}}_3$, ${\mathrm{V}}_2{\mathrm{O}}_4$ and ${\mathrm{V}}_2{\mathrm{O}}_5$ is ______ B.M. (Nearest Integer)

Acidified potassium permanganate solution oxidises oxalic acid. The spin-only magnetic moment of the manganese product formed from the above reaction is ____ B.M. (Nearest Integer)

In following pairs, the one in which both transition metal ions are colourless is :

In neutral or faintly alkaline medium, ${\mathrm{KMnO}}_4$ being a powerful oxidant can oxidize, thiosulphate almost quantitatively, to sulphate. In this reaction overall change in oxidation state of manganese will be :

The difference in oxidation state of chromium in chromate and dichromate salts is ______

Metals generally melt at very high temperature. Amongst the following, the metal with the highest melting point will be

Manganese (VI) has ability to disproportionate in acidic solution. The difference in oxidation states of two ions it forms in acidic solution is ____

The metal ion (in gaseous state) with lowest spin-only magnetic moment value is

Cerium (IV) has a noble gas configuration. Which of the following is correct statement about it?

Among the following, which is the strongest oxidizing agent ?

The major components in "Gun Metal" are:

Which one of the following when dissolved in water gives coloured solution in nitrogen atmosphere?

The number of $4f$ electrons in the ground state electronic configuration of ${\mathrm{Gd}}^{2+}$ is ______.
[Atomic number of Gd = 64]

For above chemical reactions, identify the correct statement from the following

What is the correct order of the following elements with respect to their density?

The incorrect statement among the following is:

${\mathrm{Cu}}^{2+}$ salt reacts with potassium iodide to give :

Potassium permanganate on heating at 513 K gives a product which is :

The addition of dilute NaOH to ${\mathrm{Cr}}^{3+}$ salt solution will give:

Given below are two statements :
Statement I: ${\mathrm{CeO}}_2$ can be used for oxidation of aldehydes and ketones.
Statement II : Aqueous solution of ${\mathrm{EuSO}}_4$ is a strong reducing agent.
In the light of the above statements, choose the correct answer from the opt …

In which of the following pairs, the outer most electronic configuration will be the same ?

The set having ions which are coloured and paramagnetic both is:

Which one of the following lanthanoids does not form ${\mathrm{MO}}_2$?
[ $M$ is lanthanoid metal ]

Dichromate ion is treated with base, the oxidation number of Cr in the product formed is ______