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

    16
    ReputationRep:
    Name:  1470343243074-1676330518.jpg
Views: 64
Size:  518.4 KB Attachment 567658567660 Here is my answer to part c of this question.
    Firstly, I want to know whether my squiggly line is drawn correctly because I don't normally use it
    Secondly, I am not sure if I am supposed to join all the points together or just do a line of best fit for this kind of question. Have I done it right?
    Thirdly, for my calculation, my inital rate is 9.09*10^-4 but the answer is 6.25*10^-4, what have I done wrong?

    Many thanks
    Attached Images
      
    Offline

    10
    ReputationRep:
    Your working looks fine to me, the initial rate is the gradient of the line when t=0 as you've identified.

    I think the error in your answer arises from the fact that it is hard to accurately draw a tangent to a hand drawn line of best fit.So the error is nothing to do with your chemistry or your understanding its just a bit of human error which is hard to avoid (could use a computer to do the plot?)
    • Thread Starter
    Offline

    16
    ReputationRep:
    (Original post by MexicanKeith)
    Your working looks fine to me, the initial rate is the gradient of the line when t=0 as you've identified.

    I think the error in your answer arises from the fact that it is hard to accurately draw a tangent to a hand drawn line of best fit.So the error is nothing to do with your chemistry or your understanding its just a bit of human error which is hard to avoid (could use a computer to do the plot?)
    Thanks for the reply. So for this kind of question, am I supposed to draw line of best fi(I vaguely remembered being told to do so)? However, it doesn't seem necessary to do so in this question, so I just plotted the points together but not very accurately though.
    Thanks
    Offline

    10
    ReputationRep:
    (Original post by coconut64)
    Thanks for the reply. So for this kind of question, am I supposed to draw line of best fi(I vaguely remembered being told to do so)? However, it doesn't seem necessary to do so in this question, so I just plotted the points together but not very accurately though.
    Thanks
    I would say a line of best fit isn't necessary, it doesn't really tell you much about the data, a line that runs through the points is more informative.

    If you know about order of reactions, you can see what the graphs of concentration vs time should look like for zeroeth, first and second order reactions in the attachment which is (hopefully) attached
    Attached Images
     
    • Thread Starter
    Offline

    16
    ReputationRep:
    (Original post by MexicanKeith)
    I would say a line of best fit isn't necessary, it doesn't really tell you much about the data, a line that runs through the points is more informative.

    If you know about order of reactions, you can see what the graphs of concentration vs time should look like for zeroeth, first and second order reactions in the attachment which is (hopefully) attached
    Hi, for the curve graph, if a line of best fit is not used then it wouldn't be as curvy though because like what I did, it looks more like a straight line then a curve if I am to plot all the points together. Thanks
 
 
 
  • 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
    Brexit voters: Do you stand by your vote?
  • 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

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