d and f Block Elements · Chemistry · NEET

The lanthanide ion having four unpaired electrons is (Given : Atomic numbers of $\mathrm{Ce}=58, \mathrm{Nd}=60, \mathrm{~Tb}=65$ and $\mathrm{Ho}=67$ )

The green paramagnetic species formed by heating $\mathrm{KMnO}_4$ at 513 K is

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

Assertion A: Generally, $3 d$ transition metals have high melting points.

Reason R: Involvement of $3 d$-electrons in addition to $4 s$-electrons in the interatomic metallic bonding.

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

$$ \text { Match List I with List II : } $$

Although +3 oxidation state is most common in lanthanoids, cerium still shows +4 oxidation state because:

The calculated 'spin-only' magnetic moment $\mathrm{Ti}^{2+}\left(3 \mathrm{~d}^2\right)$ is :

Match List - I with List - II.

Choose the correct answer from the options given below :

Given below are two statements :

Statement I: Ferromagnetism is considered as an extreme form of paramagnetism.

Statement II : The number of unpaired electrons in a $\mathrm{Cr}^{2+}$ ion $(\mathrm{Z}=24)$ is the same as that of a $\mathrm{Nd}^{3+}$ ion $(\mathrm{Z}=60)$.

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

Baeyer's reagent is :

Which of the following pairs of ions will have same spin only magnetic moment values within the pair?

A. $$\mathrm{Zn}^{2+}, \mathrm{Ti}^{2+}$$

B. $$\mathrm{Cr}^{2+}, \mathrm{Fe}^{2+}$$

C. $$\mathrm{Ti}^{3+}, \mathrm{Cu}^{2+}$$

D. $$\mathrm{V}^{2+}, \mathrm{Cu}^{+}$$

Choose the correct answer from the options given below :

Which of the following set of ions act as oxidising agents?

The UV-visible absorption bands in the spectra of lanthanoid ions are 'X', probably because of the excitation of electrons involving 'Y'. The 'X' and 'Y', respectively, are : Narrow and d and f orbitals

Match List I with List II:

Choose the correct answer from the options given below:

Identify the incorrect statement.

'Spin only' magnetic moment is same for which of the following ions?

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

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

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

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

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

Choose the most appropriate answer from the options given below.

The $$\mathrm{E}^{\circ}$$ value for the $$\mathrm{Mn}^{3+} / \mathrm{Mn}^{2+}$$ couple is more positive than that of $$\mathrm{Cr}^{3+} / \mathrm{Cr}^{2+}$$ or $$\mathrm{Fe}^{3+} / \mathrm{Fe}^{2+}$$ due to change of

The pair of lanthanoid ions which are diamagnetic is

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

Assertion (A) : Ionisation enthalpy increases along each series of the transition elements from left to right. However, small variations occur.

Reason (R) : There is corresponding increase in nuclear charge which accompanies the filling of electrons in the inner d-orbitals.

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

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

Assertion (A) : Ionisation enthalpies of early actinoids are lower than for early lanthanoids.

Reason (R) : Electrons are entering 5f orbitals in actinoids which experience greater shielding from nuclear charge.

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

The stability of $$\mathrm{Cu}^{2+}$$ is more than $$\mathrm{Cu}^{+}$$ salts in aqueous solution due to -

Which of the following statements are INCORRECT?

A. All the transition metals except scandium form MO oxides which are ionic.

B. The highest oxidation number corresponding to the group number in transition metal oxides is attained in $$\mathrm{Sc}_{2} \mathrm{O}_{3}$$ to $$\mathrm{Mn}_{2} \mathrm{O}_{7}$$.

C. Basic character increases from $$\mathrm{V}_{2} \mathrm{O}_{3}$$ to $$\mathrm{V}_{2} \mathrm{O}_{4}$$ to $$\mathrm{V}_{2} \mathrm{O}_{5}$$.

D. $$\mathrm{V}_{2} \mathrm{O}_{4}$$ dissolves in acids to give $$\mathrm{VO}_{4}^{3-}$$ salts.

E. $$\mathrm{CrO}$$ is basic but $$\mathrm{Cr}_{2} \mathrm{O}_{3}$$ is amphoteric.

Choose the correct answer from the options given below:

Given below are two statements :

Statement I : Cr²⁺ is oxidising and Mn³⁺ is reducing in nature.

Statement II : Sc³⁺ compounds are repelled by the applied magnetic field.

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