Question
Which of the following arrangements does not represent the correct order of the property stated against it?
A.
$$Sc < Ti < Cr < Mn:$$ number of oxidation states
B.
$${V^{2 + }} < C{r^{2 + }} < M{n^{2 + }} < F{e^{2 + }}:$$ paramagnetic behaviour
C.
$$N{i^{2 + }} < C{o^{2 + }} < F{e^{2 + }} < M{n^{2 + }}:$$ ionic size
D.
$$C{o^{3 + }} < F{e^{3 + }} < C{r^{3 + }} < S{c^{3 + }}:$$ stability in aqueous solution
Answer :
$${V^{2 + }} < C{r^{2 + }} < M{n^{2 + }} < F{e^{2 + }}:$$ paramagnetic behaviour
Solution :
Number of unpaired electrons in $$F{e^{2 + }}$$ is less than $$M{n^{2 + }},$$ so $$F{e^{2 + }}$$ is less paramagnetic than $$M{n^{2 + }}.$$