Atom economy issue Watch

Chlorophile
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#1
Report Thread starter 4 years ago
#1
For this question:

C4H10+10F2 -> C4F10+10HF
Calculate the percentage atom economy for the formation of C4F10.

I did \frac{(4\times16)+(10\times19)}{  (4\times16)+(10\times1)+(19\time  s20)}\times100=\frac{254}{454} \times100=55.9 but the mark scheme has the answer as \frac{238}{438}\times100=54.3. Am I being an idiot or is the mark scheme wrong?

You can find the paper and mark scheme here.
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RossB97
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#2
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Check your molar mass calculations are right then check you're using the equation correctly.It's molar mass of desired product divided by molar mass of all products *100.

The mark scheme is right by the way

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Pigster
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#3
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C = 12 not 16.
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cookiesandcream3
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#4
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In the book it says differently, it says its the mass of desired product divided by the total mass of reactants x 100.
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Pigster
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#5
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If you've got a balanced equation, the mass of the reactants = mass of products, so it doesn't matter which you define it as.

4x12) + (1x19) x100 = 54.3%
(4x12) + (10x1) + (20x1)
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Chlorophile
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#6
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Oh god, I really am an idiot. Thanks -_-
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