Let’s analyze each statement individually:
Statement A: is an oil at room temperature. - (manganese heptoxide) is indeed a dark green oil that is highly unstable and explosive at room temperature. It is a covalent oxide and behaves as an acidic oxide due to its high oxidation state. Therefore, this statement is correct.
Statement B: reacts with acid to give . - (vanadium(IV) oxide) is an amphoteric oxide. It can react with acids, undergoing oxidation, to form the ion (vanadyl ion). This reaction occurs as:
Therefore, this statement is also correct.
Statement C: is a basic oxide. - (chromium(II) oxide) is a basic oxide. It reacts readily with acids to form salts and water. For example:
This confirms that behaves as a basic oxide, so this statement is correct.
Statement D: does not react with acid. - (vanadium(V) oxide) is an amphoteric oxide, meaning it can react with both acids and bases. In fact, can react with acidic solutions, such as hydrochloric acid, and undergo reduction. Therefore, this statement is incorrect.
Since statements A and C are correct, the correct answer is Option (2).
List-I Alkali Metal | List-II Emission Wavelength in nm |
---|---|
(A) Li | (I) 589.2 |
(B) Na | (II) 455.5 |
(C) Rb | (III) 670.8 |
(D) Cs | (IV) 780.0 |
If and
and , then the value of equals to: