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    Hello everyone, I have this really unusual question (see attachment). Can anyone explain why the answer can't be 1.37% but 0.68%? Because I had similar questions like this and they were right, but in this question I did the Name:  ImageUploadedByStudent Room1422314341.218036.jpg
Views: 116
Size:  58.4 KBsame method but different answer!


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    (Original post by Medically)
    Hello everyone, I have this really unusual question (see attachment). Can anyone explain why the answer can't be 1.37% but 0.68%? Because I had similar questions like this and they were right, but in this question I did the Name:  ImageUploadedByStudent Room1422314341.218036.jpg
Views: 116
Size:  58.4 KBsame method but different answer!


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    What exactly makes you think it should be multiplied by two?
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    There is no error in the zero reading on the syringe, so you only get an error on the final reading, hence you don't multiply like you would on a burette (or a balance when measuring mass change) where you make two readings (initial and final).

    It may seem strange, but a zero reading on a burette will have error, since you can be above or below the mark, whereas a syringe has a definite stop position at zero.
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    So basically when there is an error reading on the syringe, you don't multiply the error by 2, but when there is an error reading on the burette, you multiply the error by 2.

    And this is because the burette has two measures (initial and final), whereas the syringe as only one measure which is just the final.

    Please tell me if I am correct or not 😊


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    Correct.

    Although some exam boards also worry about end-point error on titrations, i.e. the uncertainty caused by determining whether the indicator has changed colour.
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    Oh okay, thank you for your help. 😊


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