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

    7
    ReputationRep:
    My class did the experiment where we found the absorbance of different glucose concentrations (0%, 0.5%, 1%, 2%, 5%, 10%) using a colorimeter but my results came up really mixed up and has no correlation whatsoever!
    What did I do wrong?
    Offline

    8
    ReputationRep:
    (Original post by Mends)
    My class did the experiment where we found the absorbance of different glucose concentrations (0%, 0.5%, 1%, 2%, 5%, 10%) using a colorimeter but my results came up really mixed up and has no correlation whatsoever!
    What did I do wrong?
    what axis did u plot absorbance on? did you reset the calorimeter using water each time? did you heat the reactants properly? did you use equal volumes of reactants?, your results should show a smooth curve either decreasing or increasing depending on the type of benedicts reagent you used.
    • Thread Starter
    Offline

    7
    ReputationRep:
    Plotted it on the x axis, how do you reset it with water and why? i heated the solution in a 90 degrees water bath for 5 mins and i did use equal volumes

    (Original post by dreamfyre)
    what axis did u plot absorbance on? did you reset the calorimeter using water each time? did you heat the reactants properly? did you use equal volumes of reactants?, your results should show a smooth curve either decreasing or increasing depending on the type of benedicts reagent you used.
    Offline

    8
    ReputationRep:
    (Original post by Mends)
    Plotted it on the x axis, how do you reset it with water and why? i heated the solution in a 90 degrees water bath for 5 mins and i did use equal volumes
    first of all absorbance is on y axis, because independent variable which is concentration is on x - axis, secondly you reset it with water by just pressing the calibrate button - this is to reset the baseline value, i.e. 0 absorbance = as clear as water.
    • Thread Starter
    Offline

    7
    ReputationRep:
    so do you put some water into a cuvette and then put it into the colorimeter then press the calibrate button and you have to do that after each solution?

    (Original post by dreamfyre)
    first of all absorbance is on y axis, because independent variable which is concentration is on x - axis, secondly you reset it with water by just pressing the calibrate button - this is to reset the baseline value, i.e. 0 absorbance = as clear as water.
 
 
 
  • 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.