1
NEET 2024
MCQ (Single Correct Answer)
+4
-1
Change Language

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

A
$$d^5$$ to $$d^4$$ configuration
B
$$d^5$$ to $$d^2$$ configuration
C
$$d^4$$ to $$d^5$$ configuration
D
$$d^3$$ to $$d^5$$ configuration
2
NEET 2024
MCQ (Single Correct Answer)
+4
-1
Change Language

The pair of lanthanoid ions which are diamagnetic is

A
$$\mathrm{Ce}^{4+}$$ and $$\mathrm{Yb}^{2+}$$
B
$$\mathrm{Ce}^{3+}$$ and $$\mathrm{Eu}^{2+}$$
C
$$\mathrm{Gd}^{3+}$$ and $$\mathrm{Eu}^{3+}$$
D
$$\mathrm{Pm}^{3+}$$ and $$\mathrm{Sm}^{3+}$$
3
NEET 2023 Manipur
MCQ (Single Correct Answer)
+4
-1
Change Language

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 :

A
(A) is correct but (R) is not correct.
B
(A) is not correct but (R) is correct.
C
Both (A) and (R) are correct and (R) is the correct explanation of (A).
D
Both (A) and (R) are correct but (R) is not the correct explanation of (A).
4
NEET 2023 Manipur
MCQ (Single Correct Answer)
+4
-1
Change Language

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 :

A
(A) is true but (R) is false.
B
(A) is false but (R) is true.
C
Both (A) and (R) are true and (R) is the correct explanation of (A).
D
Both (A) and (R) are true but (R) is not the correct explanation of (A).
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