JEE Chemistry 2026 Question with Solution

Given: Statements are given about $\text{Mn}$ and $\text{Mn}_2\text{O}_7$.

Find: Which statements among A, B, C, D are correct.

Identify principle: Very high oxidation state oxides of transition metals are generally covalent and are stabilized by oxygen through multiple bonding.

Apply the statements one by one:

1. Statement A: Manganese has electronic configuration $[\text{Ar}]\,3d^5 4s^2$ and can show a maximum oxidation state of $+7$. In $\text{Mn}_2\text{O}_7$, manganese is in its highest oxidation state. So A is correct.

2. Statement B: Oxygen stabilizes higher oxidation states of manganese by forming $p\pi-d\pi$ multiple bonds. So B is correct.

3. Statement C: $\text{Mn}_2\text{O}_7$ is a green oily liquid and is highly explosive. Such properties indicate a covalent oxide, not an ionic oxide. So C is incorrect.

4. Statement D: The structure of $\text{Mn}_2\text{O}_7$ consists of two $\text{MnO}_4$ tetrahedra sharing one common oxygen atom:

Hence it contains one bridged oxygen. So D is correct.

Conclude: Therefore, the correct statements are A, B and D only. The correct option is A.

Given: Four statements about $\text{Mn}_2\text{O}_7$ are to be checked.

Find: The correct combination.

The hint says that transition metal oxides in very high oxidation states such as $+5$, $+6$ and $+7$ tend to be covalent and acidic in nature.

So statement C can be eliminated first because it says $\text{Mn}_2\text{O}_7$ is ionic.

Now check the remaining statements:

• A is correct because manganese reaches oxidation state $+7$ in $\text{Mn}_2\text{O}_7$.
• B is correct because oxygen stabilizes high oxidation states through multiple bonding.
• D is correct because the molecule contains two tetrahedral units linked by one bridging oxygen.

Conclude: Only A, B and D are correct, so the answer is A.