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    A student made 1.10g of dipeptide H starting from 1.40g of glycine.
    Calculate the percentage yield (%) obtained. Give your answer to 3 sig. figs.

    Thanks loads to anyone who can help me; I've always had trouble with percentage yields....
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    (Original post by play_the_world)
    A student made 1.10g of dipeptide H starting from 1.40g of glycine.
    Calculate the percentage yield (%) obtained. Give your answer to 3 sig. figs.

    Thanks loads to anyone who can help me; I've always had trouble with percentage yields....
    What is there here not to understand?!

    Percentage yield = End Product / Starting Product x 100

    1.1 / 1.4 x 100 = 78.6%

    In this reaction...

    2 x glycine --> dipeptide + H20

    since the dipeptide is formed by a condensation reaction the remaining 21.4% is due to the water produced
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    Well I thought it would be more complicated than that, because the question is worth 4 marks. Thanks alot anyway.
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    Actually, I think what you're looking for is:

    % yield = [actual yield (in grams) / predicted yield (in grams) ] x 100

    To work out the predicted yield you'd have to do some moles calculations using the equation for the reaction ... which would probably be why it's worth 4 marks.
 
 
 
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