Question

Among the following pairs of ions, the lower oxidation state in aqueous solution is more stable than the other, in

• A. $Ti ^{+}, Ti ^{3+}$
• B. $Cu ^{+}, Cu ^{2+}$
• C. $Cr ^{2+}, Cr ^{3+}$
• D. $V ^{2+}, VO ^{2+}$

Answer 1

Answer: (A)

$Ti ^{+}, Ti ^{3+}$

Answer 2

As we move down in $13,14$ and $15$ groups the inertness of $s^{2}$ electrons of valence shell increases and therefore, metals in the lower portion of the group show lower oxidation state e.g., lead show $+2$ inspite of $+4$. Similarly $+3$ oxidation state of bismuth is more stable than $+5$ oxidation state. Thus, due to inert pair effect, titanium shows $+1$ oxidation state rather than $+3$.