Join TSR now and get all your revision questions answeredSign up now

How to calculate Percentage uncertainty?? Watch

    • Thread Starter
    Offline

    1
    ReputationRep:
    Here are the questions:

    Calculate the percentage uncertainty associated with the volume of sodium carbonate which you have transferred using a pipette (uncertainty associated with reading a 25cm3 class B pipette is 0.06 cm3)

    Calculate the percentage uncertainty associated with your average titre (uncertainty associated with each reading of a 50cm3 class B burette is 0.05cm3) My average titre reading was 23.7
    • PS Reviewer
    • Study Helper
    Offline

    3
    ReputationRep:
    Percentage Uncertainty = (Absolute Uncertainty / Measured Value) x 100

    Therefore:

    % for pipette = (0.06 / 25) x 100 = 0.24%


    % for burette = (0.05 / 23.7) x 100 = 0.21%
    Offline

    0
    ReputationRep:
    yarghan
    Offline

    2
    ReputationRep:
    (Original post by Nirgilis)
    Percentage Uncertainty = (Absolute Uncertainty / Measured Value) x 100

    Therefore:

    % for pipette = (0.06 / 25) x 100 = 0.24%


    % for burette = (0.05 / 23.7) x 100 = 0.21%
    Do you not multiply the second one by two (assuming the calculation for average titre was made from two values)? Sorry for re-awakening a 2 year old thread.
    • Community Assistant
    • Study Helper
    Offline

    3
    ReputationRep:
    (Original post by ERdoctor)
    Do you not multiply the second one by two (assuming the calculation for average titre was made from two values)? Sorry for re-awakening a 2 year old thread.
    yes, you do.
    Offline

    1
    ReputationRep:
    Yes you do. (Sorry for re-awaking a 4 years old comment and 6 years old post)
    Offline

    2
    ReputationRep:
    (Original post by Ahmed Alfarra)
    Yes you do. (Sorry for re-awaking a 4 years old comment and 6 years old post)
    Thank you for this. (sorry for re-surfacing an 8 year old post and 1 year old comment)
    Offline

    1
    ReputationRep:
    so the equation is going to be

    (0.06 / 25) x 100 = 0.24%

    (0.05 / 23.7) x 2 x 100 = 41%

    (sorry for re-surfacing an 8 year old post and 1 week old comment)
 
 
 
Poll
How are you feeling about Results Day?

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.