question_answer

Among the following pairs of ions, the lower oxidation state in aqueous solution is more stable than the other in [AIIMS 2005]

A) \[T{{l}^{+}},\ T{{l}^{3+}}\]

B) \[C{{u}^{+}},\ C{{u}^{2+}}\]

C) \[C{{r}^{2+}},\ C{{r}^{3+}}\]

D) \[{{V}^{2+}},\ V{{O}^{2+}}\]

Correct Answer: A

Solution :

Tl+ ions are more stable than Tl3+ and thus, Tl3+ ions change to Tl+ ions thereby acting as oxidising agents. Tl3+ compounds + 2e ® Tl+ compounds