Redox Reactions and Couple

Q. What is the difference between FeO + O2 → Fe2O3 and Fe + O2 → Fe2O3?

Q. Oxidation state of S in $N{a}_2{S}_2{O}_3$ is

1. 5
2. -1
3. 0
4. 2

Q. The Oxidation state of Mn in $K_{2}Mn{O}_4$ is

1. 2
2. 7
3. 6
4. -2

Q. For the cell $Pt|H_2\left(1atm\right)|HCl\left(0.01M\right)||HCl(pH=X)|H_2\left(0.01atm\right)|Pt$. Calculate x, when there is no flow of electricity.

Q. Oxidation state of S in $[HS{O}_4{]}^{-}$ is

1. 2
2. 4
3. 6
4. -2

Q. What is the oxidation state of Mn in Manganese (VII) oxide?

1. 7
2. 5
3. 3
4. 1

Q. Oxidation state of O in $O{F}_2$ Is

1. -2
2. 2
3. -1
4. 1