\(2H_2O_2 → 2H_2O + O_2\)
\(2NO_2 + H_2O → HNO_3 + HNO_2\)
\(MnO4^– + 4H^+ + 3e^– → MnO_2 + 2H_2O\)
\(3MnO_4^{2–} + 4H^+ → 2MnO_4^– + MnO_2 + 2H_2O\)
\(\overset{+7}{Mn}O_4^– + 4H^+ + 3e^– → \overset{+4}{Mn}O_2+ 2H_2O\)
This reaction envolves the reduction of \(MnO_4^–\) to \(MnO_2\).
So, the correct option is (C).
The term independent of $ x $ in the expansion of $$ \left( \frac{x + 1}{x^{3/2} + 1 - \sqrt{x}} \cdot \frac{x + 1}{x - \sqrt{x}} \right)^{10} $$ for $ x>1 $ is:

Two cells of emf 1V and 2V and internal resistance 2 \( \Omega \) and 1 \( \Omega \), respectively, are connected in series with an external resistance of 6 \( \Omega \). The total current in the circuit is \( I_1 \). Now the same two cells in parallel configuration are connected to the same external resistance. In this case, the total current drawn is \( I_2 \). The value of \( \left( \frac{I_1}{I_2} \right) \) is \( \frac{x}{3} \). The value of x is 1cm.
If $ \theta \in [-2\pi,\ 2\pi] $, then the number of solutions of $$ 2\sqrt{2} \cos^2\theta + (2 - \sqrt{6}) \cos\theta - \sqrt{3} = 0 $$ is:
Oxidation number, also called oxidation state, the total number of electrons that an atom either gains or loses in order to form a chemical bond with another atom.
Oxidation number of an atom is defined as the charge that an atom appears to have on forming ionic bonds with other heteroatoms. An atom having higher electronegativity (even if it forms a covalent bond) is given a negative oxidation state.
The definition, assigns oxidation state to an atom on conditions, that the atom –
Oxidation number is a formalized way of keeping track of oxidation state.
Read More: Oxidation and Reduction
Oxidation number or state of an atom/ion is the number of electrons an atom/ion that the molecule has either gained or lost compared to the neutral atom. Electropositive metal atoms, of group I, 2 and 3 lose a specific number of electrons and have always constant positive oxidation numbers.
In molecules, more electronegative atom gain electrons from a less electronegative atom and have negative oxidation states. The numerical value of the oxidation state is equal to the number of electrons lost or gained.
Oxidation number or oxidation state of an atom or ion in a molecule/ion is assigned by: