Oxidation Number

The oxidation state of Cr in  ${[\text{Cr}{({\text{NH}}_{\text{3}})}_{\text{4}}{\text{Cl}}_{\text{2}}]}^{+}$  is

Oxidation number of iodine varies from

What is the net charge on ferrous ion?                      

In which of the following compounds does chlorine have the highest oxidation number?

In which of the following compounds, is carbon in its lowest oxidation state?

The oxidation number of sulphur in ${\mathrm{S}}_2{\mathrm{O}}_7^{2-}$ is

Which of the following oxidation states is/are shown by hydrogen?

One mole of hydrazine $\left(N_2{H}_4\right)$ loses 10 moles of electrons in a reaction to form a new compound $X.$ Assuming that all the nitrogen atoms in hydrazine appear in the new compound, what is the oxidation state of nitrogen in $X$ ? (Note There is no change in the oxidation state of hydrogen in the reaction)

Which of the following oxidation states is/are shown by hydrogen?

What is the oxidation state of $\mathrm{I}$ in ${\mathrm{INO}}_3$?

What is the oxidation number of copper in brass?

The oxidation state of nitrogen in dinitrogen trioxide is:

The heating of ${\left({\mathrm{NH}}_4\right)}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ produces another chromium compound along with ${\mathrm{N}}_2$ gas. The change of the oxidation state of $\mathrm{Cr}$ in the reaction is

The formal oxidation numbers of $\text{C}\text{r}$ and $\text{C}\text{l}$ in the ions ${\mathrm{Cr}}_2{\mathrm{O}}_7^{2-}$ and $\text{C}\text{l}{\text{O}}_3^{-}$, respectively are

The sum of oxidation number of all the atoms in ${\mathrm{S}}_2{\mathrm{O}}_3^{2-}$ ion is

The oxidation states of $\mathrm{S}$ in ${\mathrm{H}}_2 {\mathrm{S}}_2{\mathrm{O}}_7$ are:

How many of the following species have formal oxidation state of $\mathrm{N}$ or $\mathrm{P}$ as $\text{'}+5\text{'}$

${\mathrm{N}}_2{\mathrm{O}}_5, {\mathrm{NO}}_3^{-}, {\mathrm{NO}}_2^{-}, {\left[{\mathrm{PO}}_4\right]}^{3-}, {\mathrm{P}}_4{\mathrm{O}}_6, {\mathrm{P}}_4{\mathrm{O}}_{10}, {\mathrm{H}}_3{\mathrm{PO}}_3$

The oxidation number of an element in a compound is evaluated on the basis of certain rules. Which of the following rules is not correct?

A. The oxidation number of hydrogen is always $+1$.

B. The algebraic sum of all the oxidation numbers of all elements in a compound is zero.

C. An element in the free or the uncombined state bears the oxidation number zero.

D. In all its compounds, the oxidation number of fluorine is $-1$.

Oxidation number of $\mathrm{N}$ in ${\mathrm{N}}_2\mathrm{O}$ is :