Question

Statement I: Of the following set of oxides \([Al_2O_3, Cr_2O_3] : [CO, N_2O] ; [Na_2O, V_2O_3] ; [Cl_2O_7, Mn_2O_7]\), the number of sets having the same nature of oxides (basic, acidic, neutral or amphoteric) are 4.
Statement II: Of the given oxides \(Na_2O, Al_2O_3, CO, Cl_2O_7\), the most basic and acidic oxides are \(Na_2O\) and \(Cl_2O_7\).
Which of the following options is correct?
(A) Both Statement I and Statement II are correct.
(B) Statement I is correct, but Statement II is incorrect.
(C) Statement I is incorrect, but Statement II is correct.
(D) Both Statement I and Statement II are incorrect.

Hint:

Amphoteric oxides can act both as acids and bases, neutral oxides do not show acidic or basic properties, basic oxides react with acids, and acidic oxides react with bases.

Answer 1

Correct Answer: 1

Step 1: Understanding the Concept:
The acidic or basic nature of an oxide depends on:
(1) The metallic or non-metallic character of the element.
(2) The oxidation state of the element in the oxide.
Highly electropositive metals form basic oxides; non-metals and metals in high oxidation states form acidic oxides; some metals in intermediate oxidation states form amphoteric oxides; and certain non-metal oxides (like CO and \(N_2O\)) are neutral.
Step 2: Detailed Explanation:
Statement I Analysis:
Set 1: \([Al_2O_3, Cr_2O_3]\)
\(Al_2O_3\): Aluminium (+3 oxidation state) is amphoteric -- reacts with both acids and bases.
\(Cr_2O_3\): Chromium in +3 oxidation state is also amphoteric.
Both are amphoteric.
Set 2: \([CO, N_2O]\)
Both carbon monoxide and nitrous oxide are neutral oxides -- they neither react with acids nor with bases.
Set 3: \([Na_2O, V_2O_3]\)
\(Na_2O\): Sodium is a highly electropositive alkali metal. Its oxide is strongly basic.
\(V_2O_3\): Vanadium in the lower +3 oxidation state behaves as a basic oxide.
Both are basic.
Set 4: \([Cl_2O_7, Mn_2O_7]\)
\(Cl_2O_7\): Chlorine in +7 oxidation state (highest). Non-metal oxide -- strongly acidic.
\(Mn_2O_7\): Manganese in +7 oxidation state. Very high oxidation state metal oxide -- strongly acidic.
Both are acidic.
All 4 sets have the same oxide nature within each pair. Statement I is CORRECT.
Statement II Analysis:
Among \(Na_2O, Al_2O_3, CO, Cl_2O_7\):
\(Na_2O\) is basic (alkali metal oxide -- most electropositive character).
\(Cl_2O_7\) is the oxide of Cl in its highest oxidation state (+7), making it the most acidic.
\(Al_2O_3\) is amphoteric and \(CO\) is neutral.
Statement II is CORRECT.
Step 3: Final Answer:
Both statements are scientifically accurate. The answer is (A).