Complete and balance the following equations: (i) 2 KMnO 4 513 K (ii) Na 2 Cr 2 O 7+2 KCl → Why is it difficult to separate lanthanoid elements in…

(a) (i) 2KMnO4 → K2MnO4 + MnO2 + O2 (ii) Na2Cr2O7 + 2KCl → K2Cr2O7 + 2NaCl (b) Their separation is difficult because they have similar ionic size and similar physical and chemical properties / Due to lanthanoid contraction.

CBSE 2026 · Region 2 · Set 1 · Q24 · 3 marks

(a)
Complete and balance the following equations :
(i)
$\displaystyle 2 \mathrm{KMnO}_{4} \xrightarrow{513 \mathrm{~K}}$
(ii)
$\displaystyle \mathrm{Na}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}+2 \mathrm{KCl} \longrightarrow$
(b)
Why is it difficult to separate lanthanoid elements in pure state ?

The d-and f-Block ElementsSome Important Compounds of Transition ElementsApplyshort_answermedium

Practice The d-and f-Block Elements →All The d-and f-Block Elements questions

(a)
Complete and balance the following equations :
(i)
$\displaystyle 2 \mathrm{KMnO}_{4} \xrightarrow{513 \mathrm{~K}}$
(ii)
$\displaystyle \mathrm{Na}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}+2 \mathrm{KCl} \longrightarrow$
(b)
Why is it difficult to separate lanthanoid elements in pure state ?

Marking-scheme solution

More from The d-and f-Block Elements

(a)Complete and balance the following equations :(i)$\displaystyle 2 \mathrm{KMnO}_{4} \xrightarrow{513 \mathrm{~K}}$(ii)$\displaystyle \mathrm{Na}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}+2 \mathrm{KCl} \longrightarrow$(b)Why is it difficult to separate lanthanoid elements in pure state ?

Marking-scheme solution

More from The d-and f-Block Elements

(a)
Complete and balance the following equations :
(i)
$\displaystyle 2 \mathrm{KMnO}_{4} \xrightarrow{513 \mathrm{~K}}$
(ii)
$\displaystyle \mathrm{Na}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}+2 \mathrm{KCl} \longrightarrow$
(b)
Why is it difficult to separate lanthanoid elements in pure state ?