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
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.
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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
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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…
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