Saturday, September 29, 2007

Chemistry Questions - Redox Reaction

How about another Chemistry Question on Redox Reactions as a food for thoughts over the weekend...

Q) 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
SimpleChemConcept

2 comments:

  1. 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.

    ReplyDelete
  2. 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

    ReplyDelete