Question

Select the correct statements among the following.

$I)$ $V_2{O}_5$ and $C{r}_2{O}_3$ are amphoteric oxides.
$II)$ Interstitial compounds of transition elements have an exact formulae.
$III)$ In its higher oxidation states, manganese forms stable compounds with oxygen and fluorine.

• A. $I,II$
• B. $II,III$
• C. $I,III$
• D. $I,II,III$

Answer 1

The correct option is C $I,III$

$I)$ $V_2{O}_5$ and $C{r}_2{O}_3$ are amphoteric oxides.
Transition metal oxides in their lower oxidation state are basic in nature.
In intermediate oxidation states, they are amphoteric in nature.
In higher oxidation state, they are acidic in nature.
$II)$ Interstitial compounds of transition elements do not have an exact formulae as they are non-stoichiometric compounds.
$III)$ In its higher oxidation states, manganese forms stable compounds with oxygen and fluorine.
For example, $M{n}_2{O}_7$ is stable. In higher oxidation state, transition metals only form fluorides as $F$ is more electronegative.
Thus, only statements $I$ and $III$ are correct.