Identify the correct statements about lanthan | vedclass

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(B) $I$. $Ce^{4+}$ $(4f^0)$ and $Tb^{4+}$ $(4f^7)$ have a strong tendency to gain an electron to reach stable configurations,thus acting as strong oxi

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$I$ & $IV$ only

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(B) $I$. $Ce^{4+}$ $(4f^0)$ and $Tb^{4+}$ $(4f^7)$ have a strong tendency to gain an electron to reach stable configurations,thus acting as strong oxidising agents. This statement is correct.$II$. $Eu^{2+}$ $(4f^7)$ and $Yb^{2+}$ $(4f^{14})$ are stable due to half-filled and fully-filled $f$-orbitals,respectively. They tend to lose an electron to reach the $+3$ state,thus acting as reducing agents. The statement in the question says they act as oxidising agents,which is incorrect.$III$. Mischmetal consists of approximately $95 \%$ lanthanoid metal and $5 \%$ iron,along with traces of $S, C, Ca,$ and $Al$. The statement in the question incorrectly reverses the percentages. This statement is incorrect.$IV$. $La^{3+}$ $([Xe] 4f^0)$ and $Ce^{4+}$ $([Xe] 4f^0)$ have no unpaired electrons,making them diamagnetic. This statement is correct.Therefore,statements $I$ and $IV$ are correct.

Identify the correct statements about lanthanoids:
$I$. $Ce^{4+}$ and $Tb^{4+}$ act as oxidising agents.
$II$. $Eu^{2+}$ and $Yb^{2+}$ act as reducing agents.
$III$. Mischmetal is an alloy of $95 \%$ lanthanoid metal and $5 \%$ iron.
$IV$. $La^{3+}$ and $Ce^{4+}$ are diamagnetic in nature.

Similar Questions

Although $(+3)$ oxidation state is the characteristic oxidation state of lanthanoids,cerium shows $(+4)$ oxidation state also. Why?

Arrange the ions $Ce^{3+}$,$La^{3+}$,$Pm^{3+}$,and $Yb^{3+}$ in the increasing order of their ionic radii.

Arrange the following metal complexes/compounds in the increasing order of spin-only magnetic moment. Presume all three are high-spin systems.
(Atomic numbers: $Ce = 58$,$Gd = 64$,and $Eu = 63$.)
$(a)$ $(NH_4)_2[Ce(NO_3)_6]$
$(b)$ $Gd(NO_3)_3$
$(c)$ $Eu(NO_3)_3$
Answer is:

Which of the following elements exhibits a $+4$ oxidation state?

Larger number of oxidation states are exhibited by the actinoids than those by the lanthanoids,the main reason being

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Identify the correct statements about lanthanoids:$I$. $Ce^{4+}$ and $Tb^{4+}$ act as oxidising agents.$II$. $Eu^{2+}$ and $Yb^{2+}$ act as reducing agents.$III$. Mischmetal is an alloy of $95 \%$ lanthanoid metal and $5 \%$ iron.$IV$. $La^{3+}$ and $Ce^{4+}$ are diamagnetic in nature.