Oxidation Number

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

The reactivity of the following compounds toward water is in the order

What is the similarities and the difference between the oxidation number and oxidation state.

Calculate the oxidation state of the alkaline earth metal in the compound $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$.

What is the oxidation state of the alkaline earth metal in the compound $\mathrm{MgO}$?

The equivalent weight of $\mathrm{Fe}$ in ${\mathrm{Fe}}_2{\mathrm{O}}_3$ is (Atomic mass of $\mathrm{Fe}=56 \mathrm{g}{ \mathrm{mol}}^{-1}$ )

${\mathrm{CrO}}_5$ has a structure as shown below:

The oxidation number of chromium in the above compound 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

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 $-1$.

How much charge is required for the oxidation of $1$ mole of ${\mathrm{S}}_2{\mathrm{O}}_3^{-2}$ to ${\mathrm{S}}_4{\mathrm{O}}_6^{-2}?$

How many moles of ${\mathrm{KMnO}}_4$ are reduced by $1 \mathrm{mole}$ of ferrous oxalate in acidic medium:-