Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
If $M$ is element of actinoids series, the degree of complex formation decreases in the order
Chemistryd and f Block ElementsJIPMERJIPMER 2018
Options:
  • A $\mathrm{M}^{4+} \gt \mathrm{M}^{3+} \gt \mathrm{MO}_2^{2+} \gt \mathrm{MO}_2^{+}$
  • B $\mathrm{M}^{4+} \gt \mathrm{MO}_2^{2+} \gt \mathrm{M}^{3+} \gt \mathrm{MO}_2^{+}$
  • C $\mathrm{MO}_2^{+} \gt \mathrm{MO}_2^{2+} \gt \mathrm{M}^{3+} \gt \mathrm{M}^{4+}$
  • D $\mathrm{MO}_2^{2+} \gt \mathrm{MO}_2^{+} \gt M^{4+} \gt M^{3+}$
Solution:
1528 Upvotes Verified Answer
The correct answer is: $\mathrm{M}^{4+} \gt \mathrm{MO}_2^{2+} \gt \mathrm{M}^{3+} \gt \mathrm{MO}_2^{+}$
The higher the charge on the metal ion, smaller is the ionic size and more is the complex forming ability. Thus, the degree of complex formation decreases in the order
$\mathrm{M}^{4+} \gt \mathrm{MO}_2^{2+} \gt \mathrm{M}^{3+} \gt \mathrm{MO}_2^{+}$
The higher tendency of complex formation of $\mathrm{MO}_2^{2+}$ as compared to $\mathrm{M}^{3+}$ is due to high concentration of charge on metal atom M.

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.