Statements on Nature and Acidic Basic Character of Oxides

To determine the correctness of Statement I and Statement II, let us analyze each statement individually:

Analysis of Statement I:

We are given four pairs of oxides:

1. First Pair: $[\text{Al}_2\text{O}_3, \text{Cr}_2\text{O}_3]$

   • $\text{Al}_2\text{O}_3$ (Aluminium oxide) is an amphoteric oxide.
   • $\text{Cr}_2\text{O}_3$ (Chromium(III) oxide) is also an amphoteric oxide.
   • Both oxides in this pair have the same nature (amphoteric).

2. Second Pair: $[\text{Cl}_2\text{O}_7, \text{Mn}_2\text{O}_7]$

   • $\text{Cl}_2\text{O}_7$ (Dichlorine heptoxide) is an acidic oxide (anhydride of $\text{HClO}_4$).
   • $\text{Mn}_2\text{O}_7$ (Manganese(VII) oxide) is an acidic oxide because transition metals in very high oxidation states ($+7$) exhibit acidic behavior (anhydride of $\text{HMnO}_4$).
   • Both oxides in this pair have the same nature (acidic).

3. Third Pair: $[\text{Na}_2\text{O}, \text{V}_2\text{O}_3]$

   • $\text{Na}_2\text{O}$ (Sodium oxide) is a strong basic oxide.
   • $\text{V}_2\text{O}_3$ (Vanadium(III) oxide) is a basic oxide (vanadium in lower oxidation states forms basic oxides).
   • Both oxides in this pair have the same nature (basic).

4. Fourth Pair: $[\text{CO}, \text{N}_2\text{O}]$

   • $\text{CO}$ (Carbon monoxide) is a neutral oxide.
   • $\text{N}_2\text{O}$ (Dinitrogen oxide) is a neutral oxide.
   • Both oxides in this pair have the same nature (neutral).

Thus, all $4$ pairs contain oxides of the same nature. Therefore, Statement I is true.

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Analysis of Statement II:

Among the given set of oxides: $\text{Na}_2\text{O}, \text{Al}_2\text{O}_3, \text{CO}$, and $\text{Cl}_2\text{O}_7$:

• $\text{Na}_2\text{O}$ is an alkali metal oxide which reacts vigorously with water to form the strong base $\text{NaOH}$, making it the most basic oxide in the group.
• $\text{Cl}_2\text{O}_7$ is a non-metallic oxide with chlorine in its highest oxidation state ($+7$). It reacts with water to give perchloric acid ($\text{HClO}_4$), one of the strongest inorganic acids, making it the most acidic oxide in the group.
• $\text{Al}_2\text{O}_3$ is amphoteric, and $\text{CO}$ is neutral.

Therefore, $\text{Na}_2\text{O}$ is the most basic oxide and $\text{Cl}_2\text{O}_7$ is the most acidic oxide among the given choices. Thus, Statement II is true.

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Conclusion:

Since both Statement I and Statement II are true, the correct option is A.