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

    2
    ReputationRep:
    (Original post by archibald300)
    Yh I swear that's how you're supposed to work it out right?
    Yeah think so it was the only way I could work its empircal formula out, man im so tired.....
    Offline

    12
    ReputationRep:
    I'm not great on reversible reactions. One question was about a change in pressure and the effect on the rate... I think. And one was an increase in temp and the effect on yield?

    It was slightly exothermic... wasn't the enthalpy change -9 kJ?

    A pressure difference would alter the rate of reaction.... but not affect any yield if 2 moles were produced either way. But I cannnot remember what way round the questions were.
    Offline

    2
    ReputationRep:
    Don't worry - a lot of my friends got the same too
    Me too! I have officially completed 6 out of 28 exams!
    Just take a short break, then get back to revising otherwise you feel really guilty for not doing stuff which is the worst.
    Have you got an exam tmoz?
    (Original post by gpit6903)
    Yeah think so it was the only way I could work its empircal formula out, man im so tired.....
    Offline

    2
    ReputationRep:
    (Original post by Darwinion)
    I'm not great on reversible reactions. One question was about a change in pressure and the effect on the rate... I think. And one was an increase in temp and the effect on yield?
    Is anyone going to upload a unofficial marking scheme,

    we need to try and remember the questions....

    Increase in temp and pressure = increase in rate of reaction

    increase in pressure = no change in yield

    increase in temp = less yield (i think it asked that or equivalent other way round)
    Offline

    2
    ReputationRep:
    For both the rate decreased
    For the temp one the yield increased ( i think - forward react was exo?)
    For pressure i put no change because 2 moles either side

    (Original post by Emm22)
    What answers did you guys get for the equilibrium questions?
    Offline

    1
    ReputationRep:
    (Original post by gpit6903)
    Is anyone going to upload a unofficial marking scheme,

    we need to try and remember the questions....

    Increase in temp and pressure = increase in rate of reaction

    increase in pressure = no change in yield

    increase in temp = less yield (i think it asked that or equivalent other way round)
    The question was for equilibrium:
    Originally at 500 degrees then they asked how a lower temp of 400 would effect rate and yield

    Lowered pressure from 4atm to 2atm and asked in effect on the rate and yield
    Offline

    12
    ReputationRep:
    i thought pressure didn't have an effect on rate of reaction??
    Offline

    2
    ReputationRep:
    (Original post by Emm22)
    The question was for equilibrium:
    Originally at 500 degrees then they asked how a lower temp of 400 would effect rate and yield

    Lowered pressure from 4atm to 2atm and asked in effect on the rate and yield
    Either way I think i got it the right way round, or answered the question completely wrong.... oh well

    I hate forgetting the questions after
    Offline

    1
    ReputationRep:
    (Original post by Queenie123)
    i thought pressure didn't have an effect on rate of reaction??
    I don't know, does a lower pressure affect the rate of reaction
    • Community Assistant
    Online

    19
    ReputationRep:
    For the one where you had to find the x of h2o, I did not really understand it and I wrote 8 as an answer.
    Next to the equation I wrote the mass, molar mass and moles for each, but do you think I would get any marks for this?
    Offline

    2
    ReputationRep:
    (Original post by Emm22)
    I don't know, does a lower pressure affect the rate of reaction
    increasing the pressure on a reaction involving reacting gases increases the rate of reaction...

    (
    http://www.chemguide.co.uk/physical/.../pressure.html)


    so i guess a lower pressure equals a lower rate of reaction
    Offline

    0
    ReputationRep:
    How did you guys find the paper in general? Because I'm having bad feeling about how I've done in mine!😬


    Posted from TSR Mobile
    Offline

    4
    ReputationRep:
    How did people include all those symbols for the galvanisation one?
    Offline

    0
    ReputationRep:
    (Original post by Queenie123)
    i thought pressure didn't have an effect on rate of reaction??
    No it does, pressure and temperature have an effect on the yield, its the catalyst that doesn't have any effect on the yield
    Offline

    12
    ReputationRep:
    Ahhh yes! The temperature in the question was lowered to 400 not raised. So the forward yield increased as the reaction was exothermic. The equilibrium moves in the direction to counteract any change.

    Increase in pressure always increases rate as there is less space for the particles to move around in so they collide more frequently. But it won't increase yield if the same number of moles are produced both ways (as was the case in our question).
    Offline

    0
    ReputationRep:
    I found it okish although I messed up the % of oxygen question. You'll be fine don't worry 😊


    Posted from TSR Mobile
    Offline

    9
    ReputationRep:
    (Original post by ITSJDOG)
    How did you guys find the paper in general? Because I'm having bad feeling about how I've done in mine!😬


    Posted from TSR Mobile
    same- I was completely not confident in my answers, unlike biology. My friend said she found the chemistry easier than the biology, but for me, it was the other way around!
    Offline

    2
    ReputationRep:
    What did people get for the mass question.... i got 9kg
    Offline

    0
    ReputationRep:
    How did everyone find it today?
    Offline

    0
    ReputationRep:
    (Original post by Dhdhdhsh)
    How did everyone find it today?
    Okish how did you find it?


    Posted from TSR Mobile
 
 
 
  • 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
    What newspaper do you read/prefer?
  • 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.