Results are out! Find what you need...fast. Get quick advice or join the chat
Hey there Sign in to join this conversationNew here? Join for free

Oxidation of ethanedioate ions by acidified potassium manganate(VII)

Announcements Posted on
Live webchat: Student Finance explained - on TSR from 2 - 3pm 17-09-2014
Got a question about Student Finance? Ask the experts this week on TSR! 14-09-2014
    • Thread Starter
    • 0 followers
    Offline

    ReputationRep:
    Hi, I am really stuck on this question about the molar ratios in this question, in fact I am not sure where to start. All I have done is work out the oxidation numbers, anyway here it is:

    In acid solution, potassium manganate(VII) acts as an oxidising agent
    and reacts according to the half-equation:

    5e− + MnO4− + 8H+ → Mn^2+ + 4H2O

    Acidified potassium manganate(VII) will oxidise ethanedioate ions (C2O42−)
    to carbon dioxide.

    What is the mole ratio (MnO4− : C2O4^2−) in which these ions react together?

    Can anyone offer any clues? Thank you!
    • 48 followers
    Offline

    ReputationRep:
    try writing out the oxidation of C2O42− to CO2 with electrons first, then multiply both equations so that the electrons are the same...
    • Thread Starter
    • 0 followers
    Offline

    ReputationRep:
    oh thank you, I finally worked it out to be 2:5 I think..
    • 48 followers
    Offline

    ReputationRep:
    (Original post by escondido)
    oh thank you, I finally worked it out to be 2:5 I think..
    Yup

    2MnO4- + 16H+ + 5C2O42- --> 2Mn2+ + 8H2O + 10CO2
    • 4 followers
    Offline

    ReputationRep:
    Urgh. Nasty IUPAC-ness. What is wrong with the name oxalate?
    • 48 followers
    Offline

    ReputationRep:
    (Original post by cpchem)
    Urgh. Nasty IUPAC-ness. What is wrong with the name oxalate?
    Yeah I know, I was quite miffed when I got to university since they don't really use the IUPAC names for a lot of things...the trivial and IUPAC versions should both be taught and tested :yep:
    • 0 followers
    Offline

    ReputationRep:
    do you know the order of reaction with regards to all the reactants? I'm pretty stuck and in desperate need of help :/
    • 11 followers
    Offline

    ReputationRep:
    (Original post by jimmcc)
    do you know the order of reaction with regards to all the reactants? I'm pretty stuck and in desperate need of help :/
    This is quite an old thread. You'd be better off making a new one asking your question there
Updated: April 13, 2012
New on TSR

Writing your personal statement

Our free PS builder tool makes it easy

Article updates
Reputation gems:
You get these gems as you gain rep from other members for making good contributions and giving helpful advice.