Hey there! Sign in to join this conversationNew here? Join for free
    • Thread Starter

    The feasibility of these displacement reactions can be predicted from the E  values above.
    2KCl(aq) + Br2(l) solution changes from colourless to red-brown
    1. Cl2(g) + 2e ⇌ 2Cl (aq)

    2Br-(aq)⇌2Br(l) + 2e-

    E   = +1.36 V for 1

    E   = -1.07 V for 2

    E = +0.29 V is positive so the reaction is feasible

    how is the final value +0.29? I thought it was the negative value which had its sign changed :

    +1.36 + 1.07 as it has its sign switched?
    the answer won't give me 0.29 though.. where am I going wrong? please help

    I thought thats how you calculate e.m.f

    Hmmmm, well, to be honest, I don't think the reaction should be feasible! I mean, this is a displacement reaction but bromine is less reactive than chlorine so it won't be able to displace the chlorine from KCl!

    Using the two electrode potentials given, the only reaction that would be feasible is if the bromine was oxidised to bromide ions and the chlorine was reduced to chloride ions!

    At least this is what I think ! Hopefully someone else can shed some more light on this
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    Brussels sprouts
    Help with your A-levels

    All the essentials

    The adventure begins mug

    Student life: what to expect

    What it's really like going to uni


    Essay expert

    Learn to write like a pro with our ultimate essay guide.

    Uni match

    Uni match

    Our tool will help you find the perfect course for you

    Study planner

    Create a study plan

    Get your head around what you need to do and when with the study planner tool.

    Study planner

    Resources by subject

    Everything from mind maps to class notes.

    Hands typing

    Degrees without fees

    Discover more about degree-level apprenticeships.

    A student doing homework

    Study tips from A* students

    Students who got top grades in their A-levels share their secrets

    Study help links and info

    Can you help? Study help unanswered threadsRules and posting guidelines

    Sponsored content:



    Find out how a Higher Education Achievement Report can help you prove your achievements.

    Groups associated with this forum:

    View associated groups
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

    Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

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