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

    2
    ReputationRep:
    The question:

    A steel vessel of volume 2.0 dm3 has introduced into it 0.20 mol of SO3, 0.040 mol of SO2 and 0.010 mol of O2.

    By calculation of the apparent value of KC show that this mixture is not at equilibrium, and explain in which direction the system will move in order to achieve equilibrium at a temperature of 800K.
    The value of KC at this temperature is 1.7 * 10^-6 mol-1 dm3

    2SO2(g) + O2 (g) <---> 2SO3

    delta H = -196 kJ mol-1

    What I have done so far: This is going to look messy

    1.7*10^-6 = (SO3)^2/((SO2)^2*(O2))
    Do I just substitute the molar values of the components next and see how it compares to the answer in the question?
    Also the bit about the temperature doesn't make sense - is it increasing or decreasing?

    Thanks for helping, I'm really bad at these type of questions
    • Thread Starter
    Offline

    2
    ReputationRep:
    Anyone??
    Offline

    2
    ReputationRep:
    (Original post by alde123)
    The question:

    A steel vessel of volume 2.0 dm3 has introduced into it 0.20 mol of SO3, 0.040 mol of SO2 and 0.010 mol of O2.

    By calculation of the apparent value of KC show that this mixture is not at equilibrium, and explain in which direction the system will move in order to achieve equilibrium at a temperature of 800K.
    The value of KC at this temperature is 1.7 * 10^-6 mol-1 dm3

    2SO2(g) + O2 (g) <---> 2SO3

    delta H = -196 kJ mol-1

    What I have done so far: This is going to look messy

    1.7*10^-6 = (SO3)^2/((SO2)^2*(O2))
    Do I just substitute the molar values of the components next and see how it compares to the answer in the question?
    Also the bit about the temperature doesn't make sense - is it increasing or decreasing?

    Thanks for helping, I'm really bad at these type of questions
    All I know is that if a reaction is exothermic like this one, at a higher temperature the position of equilibrium shifts to the right favouring the formation of the product, so 2SO3. Does that help at all? I'm not sure how to explain the other part of the question, sorry.
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by Elle_w)
    All I know is that if a reaction is exothermic like this one, at a higher temperature the position of equilibrium shifts to the right favouring the formation of the product, so 2SO3. Does that help at all? I'm not sure how to explain the other part of the question, sorry.
    Thanks for helping. One of my friends explained it to me at school - turns out I read the question wrong

    The temperature is just a stated temperature - it hasn't increased or decreased from anything. The other part of the question was just to prove that it hasn't reached equilibrium yet i.e. just plug the values (moles divided by two) into the Kc expression.
 
 
 
  • 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
    Would you like to hibernate through the winter months?
    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

    Rosette

    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:

    HEAR

    HEAR

    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.