Choose the correct statements from the following:
A. \( Mn_2O_7 \) is an oil at room temperature
B. \( V_2O_4 \) reacts with acid to give \( VO_2^{2+} \)
C. \( CrO \) is a basic oxide
D. \( V_2O_5 \) does not react with acid
Choose the correct answer from the options given below:
A. \( Mn_2O_7 \) is an oil at room temperature
B. \( V_2O_4 \) reacts with acid to give \( VO_2^{2+} \)
C. \( CrO \) is a basic oxide
D. \( V_2O_5 \) does not react with acid
Choose the correct answer from the options given below:
- A, B and D only
- A and C only
- A, B and C only
- B and C only
The Correct Option is B
Approach Solution - 1
Let's analyze each statement given in the question to determine which are correct:
- Statement A: \(Mn_2O_7\) is an oil at room temperature.
This statement is correct. Manganese heptoxide (\(Mn_2O_7\)) is a volatile liquid that exists as an oily green liquid at room temperature. It is known for being a dangerous oxidizing agent and can decompose explosively. - Statement B: \(V_2O_4\) reacts with acid to give \(VO_2^{2+}\).
This statement is incorrect. \(V_2O_4\) is actually a vanadium(IV) oxide, which does not react with acid to directly give \(VO_2^{2+}\) ions. Typically, vanadium compounds form a different set of oxidation states related to the oxidation and reduction processes. - Statement C: \(CrO\) is a basic oxide.
This statement is correct. Chromium(II) oxide (\(CrO\)) is considered a basic oxide. It can react with acids to form salts and water, which is characteristic behavior of basic oxides. - Statement D: \(V_2O_5\) does not react with acid.
This statement is incorrect. Vanadium(V) oxide (\(V_2O_5\)) does react with acids. It's an amphoteric oxide and can react with both acids and bases, forming different salts like vanadates.
Based on the analysis, the correct statements are A and C. Thus, the option "A and C only" is the correct answer.
Approach Solution -2
Let’s analyze each statement individually:
Statement A: \( \text{Mn}_2\text{O}_7 \) is an oil at room temperature. - \( \text{Mn}_2\text{O}_7 \) (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: \( \text{V}_2\text{O}_4 \) reacts with acid to give \( \text{VO}_2^{2+} \). - \( \text{V}_2\text{O}_4 \) (vanadium(IV) oxide) is an amphoteric oxide. It can react with acids, undergoing oxidation, to form the \( \text{VO}_2^{2+} \) ion (vanadyl ion). This reaction occurs as:
\[ \text{V}_2\text{O}_4 + 2\text{H}^+ \to 2\text{VO}_2^{2+} + \text{H}_2\text{O} \]
Therefore, this statement is also correct.
Statement C: \( \text{CrO} \) is a basic oxide. - \( \text{CrO} \) (chromium(II) oxide) is a basic oxide. It reacts readily with acids to form salts and water. For example:
\[ \text{CrO} + 2\text{HCl} \to \text{CrCl}_2 + \text{H}_2\text{O} \]
This confirms that \( \text{CrO} \) behaves as a basic oxide, so this statement is correct.
Statement D: \( \text{V}_2\text{O}_5 \) does not react with acid. - \( \text{V}_2\text{O}_5 \) (vanadium(V) oxide) is an amphoteric oxide, meaning it can react with both acids and bases. In fact, \( \text{V}_2\text{O}_5 \) 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).
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