Redox Reactions...

Which reaction involves neither oxidation nor reduction?

The oxidation states of sulphur in the anions, $$SO_{3}^{2-}$$, $$S_{2}O_{4}^{2-}$$ and $$S_{2}O_{6}^{2-}$$ follow the order :

The oxidation state of the most electronegative atom in each of the product in the following reaction is
$$H_{2}+O_{2}\rightarrow H_{2}O_{2}+H_{2}O$$

Which of the following is a redox reaction?

When ammonium nitrate is gently heated, an oxide of nitrogen is formed. What is the oxidation state of nitrogen in this oxide?

Iron shows least oxidation state in which of the following?

In which one of the following compounds does oxygen have an oxidation number of $$+2$$?

The oxidation number of $$Mn$$ in potassium permanganate is :

In which of the following compounds, is the oxidation number of sulphur is the least?

Which of the following does not involve the change of valency?