Chemistry - Redox Reactions Question with Solution | TestHub

Let us calculate the oxidation state of the underlined atom in each molecule.

For option (1):
Oxidation state of P in ${\text{P}}_4{\text{O}}_6$ is $+3$.
Oxidation state of Cl in ${\text{Cl}}_2{\text{O}}_7$ is $+7$.
Oxidation state of Al in ${\text{AlH}}_3$ is $+3$.
Order: $+3<+7>+3$ (Incorrect)

For option (2):
Oxidation state of P in ${\text{P}}_4{\text{O}}_{10}$ is $+5$.
Oxidation state of S in ${\text{SO}}_3$ is $+6$.
Oxidation state of O in ${\text{H}}_2\text{O}$ is $-2$.
Order: $+5<+6>-2$ (Incorrect)

For option (3):
Oxidation state of N in ${\text{N}}_2{\text{O}}_5$ is $+5$.
Oxidation state of Al in ${\text{Al}}_2{\text{O}}_3$ is $+3$.
Oxidation state of S in ${\text{H}}_2\text{S}$ is $-2$.
Order: $+5>+3>-2$ (Correct)

For option (4):
Oxidation state of Pb in ${\text{PbO}}_2$ is $+4$.
Oxidation state of N in ${\text{N}}_2{\text{O}}_3$ is $+3$.
Oxidation state of S in ${\text{SO}}_3$ is $+6$.
Order: $+4>+3<+6$ (Incorrect)