How about another O Level Chemistry Question on Redox Reactions as a food for thoughts over the weekend…
Question:
Which of the following conversions is a redox reaction (involves oxidation/reduction)?
A)H+ => H20
B)NO2 => NO3^-
C)SO2 => SO3^2-
D)SO3 => SO4^2-
Enjoy and take care.
Rgds,
Sean, Master Trainer @
SimpleChemConcept
Thanks alot Zhengning!!
I have an exam tomorrow , and I was still confused with redox reactions involving covalent bonds until I read your solution. I am relieved now as I am more confident in solving them and also because The Sean has confirmed it.
Thanks again…
Well Done Zhengning! You are Right!
This is exatly the approach in answering such question testing on the Oxidation States/Numbers.
Do share this with your friends, siblings and peers alike.
PS: Good for you to type out the detailed working and share with all.
Sean
SimpleChemConcepts
I’ll give this question a try.
A)H+ => H20
The oxidation state(number) of H is +1. To find the oxidation state of H in H2O, form eqn: 2H + (-2) = 0
Hence, oxidation state of H in H2O is +1.
A is not the answer.
B)NO2 => NO3^-
Find the oxidation state of N in NO2 and NO3^-.
Eqn: N + (-2 X 2) = 0
N in NO2 = +4
Eqn: N + (-2 X 3) = -1
N in NO3^- = +5
This could be the answer.
C)SO2 => SO3^2-
Find the oxidation state of S in SO2 and SO3^2-.
Eqn: S + (-2 X 2) = +4
S in SO2 = +4
Eqn: S + (-2 X 3) = -2
S in SO3^- = +4
C is not the answer.
D)SO3 => SO4^2-
Similarly, we will get +6 for S in both SO3 and SO4^2-
So…. (B) is the answer.