What is the alteration in the oxidation state of carbon in the given reaction?

\(\mathrm{{CH_4}_{(g)} + 4{Cl_2}_{(g)} \rightarrow {CCl_4}_{(l)} + 4 HCl_{(g)}}\)

The oxidation state of Cr in ${\mathrm{CrO}}_6$ is:

The correct order of N-compounds in its decreasing order of oxidation states is :

1. ${\mathrm{HNO}}_3,$ $\mathrm{NO},$ ${\mathrm{N}}_2,$ ${\mathrm{NH}}_4\mathrm{Cl}$

2. ${\mathrm{HNO}}_3,\hspace{0.17em}\mathrm{NO},\hspace{0.17em}{\mathrm{NH}}_4\mathrm{Cl},\hspace{0.17em}{\mathrm{N}}_2$

3. ${\mathrm{HNO}}_3,\hspace{0.17em}{\mathrm{NH}}_4\mathrm{Cl},\hspace{0.17em}\mathrm{NO},\hspace{0.17em}{\mathrm{N}}_2$

4. ${\mathrm{NH}}_4\mathrm{Cl},\hspace{0.17em}{\mathrm{N}}_2,\hspace{0.17em}\mathrm{NO},\hspace{0.17em}{\mathrm{HNO}}_3$

(a) H₂O₂ + O₃ → H₂O + 2O₂ 

(b) H₂O₂ + Ag₂O → 2Ag + H₂O + O₂ 

The role of hydrogen peroxide in the above reactions is respectively:

Oxidation numbers of P in ${\mathrm{PO}}_4^{3-}$, of S in ${\mathrm{SO}}_4^{2-}$ and that of Cr in ${\mathrm{Cr}}_2{\mathrm{O}}_7^{2-}$are respectively:
1. +5, +6 and +6
2. +3, +6 and +5
3. +5, +3 and +6
4. -3, +6 and +6

The oxidation states(O.S.) of sulphur in the anions ${{\mathrm{SO}}_3}^{2-},$ ${\mathrm{S}}_2{{\mathrm{O}}_4}^{2-}$ $\mathrm{and}$ ${\mathrm{S}}_2{{\mathrm{O}}_6}^{2-}$ follow the order:

1. ${\mathrm{S}}_2{{\mathrm{O}}_4}^{2-}<{{\mathrm{SO}}_3}^{2-}<{\mathrm{S}}_2{{\mathrm{O}}_6}^{2-}$

2. ${{\mathrm{SO}}_3}^{2-}<{\mathrm{S}}_2{{\mathrm{O}}_4}^{2-}<{\mathrm{S}}_2{{\mathrm{O}}_6}^{2-}$

3. ${\mathrm{S}}_2{{\mathrm{O}}_4}^{2-}<{\mathrm{S}}_2{{\mathrm{O}}_6}^{2-}<{{\mathrm{SO}}_3}^{2-}$

4. ${\mathrm{S}}_2{{\mathrm{O}}_6}^{2-}<{\mathrm{S}}_2{{\mathrm{O}}_4}^{2-}<{{\mathrm{SO}}_3}^{2-}$

If the oxidation numbers of A, B, and C are + 2, +5, and –2 respectively, then the possible formula of the compound is:

Which of the following compounds contains iron (Fe) in the zero oxidation state?