Oxidation Number

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

The oxidation number of chromium in the above compound is 

${\mathrm{CrO}}_5$ has structure as shown

The oxidation number of chromium in the above compound is _____.$(+6/+10)$

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

The oxidation state of chromium in the final product formed by the reaction between $\mathrm{KI}$ and acidified potassium dichromate solution is

$1$ mole of ${\mathrm{FeSO}}_4$ (atomic weight is $55.84 \mathrm{g} {\mathrm{mol}}^{-1}$) is oxidized to ${\mathrm{Fe}}_2{\left({\mathrm{SO}}_4\right)}_3$. Calculate the equivalent weight of ferrous ion

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 species with an atom in $+6$ oxidation state is

Sulphur and rest of the elements of group 16 are less electronegative than oxygen. Therefore, their atoms cannot take up electrons easily. They can acquire ns²np⁶ configuration by sharing two electrons with the atoms of other elements and thus, exhibit +2 oxidation state in their compounds. In addition to this, their atoms have vacant d-orbitals in their valence shell to which electrons can be promoted from the p and s-orbitals of the same shell. As a result, they can show +4 and +6 oxidation states.

Like sulphur, oxygen does not show +4 and +6 oxidation states. The reason is :

Sulphur and rest of the elements of group 16 are less electronegative than oxygen. Therefore, their atoms cannot take up electrons easily. They can acquire ns²np⁶ configuration by sharing two electrons with the atoms of other elements and thus, exhibit +2 oxidation state in their compounds. In addition to this, their atoms have vacant d-orbitals in their valence shell to which electrons can be promoted from the p and s-orbitals of the same shell. As a result, they can show +4 and +6 oxidation states.

The oxidation state of sulphur in S₈, SO₃ and H₂S respectively are : 

In the periodic table, oxidation state _____ across a period.

The oxidation state of $\mathrm{Cr}$ in ${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ is _____.

Which of the following elements have an oxidation number of -1.

Which oxidation state is exhibited by the alkaline earth metals?