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Topic: Limiting reagent, percent yield...*delete me*  (Read 3867 times)

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Offline prncess23

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Limiting reagent, percent yield...*delete me*
« on: November 02, 2008, 04:56:11 AM »
2.1g of cyclohexene is reacted with 6.0g of bromine to yield 2.0 g 1,2-dibromocyclohexane.

a) what is the expected product?
b) which is the limiting reagent
c) what is the expected yield?
d) what is the percent yield?

Offline Astrokel

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Re: Limiting reagent, percent yield...*delete me*
« Reply #1 on: November 02, 2008, 05:00:45 AM »
hi prncess23,

you have to show some work so we know where you have gone wrong. Start off with balanced equation then work with moles.
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Offline prncess23

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Re: Limiting reagent, percent yield...
« Reply #2 on: November 02, 2008, 05:54:40 AM »
i got this far...

i got
2.1 g cyclohexene (1 mole/82.14g)=0.026 moles cyclohexene
6.0g br2(1 mole/159.81g)=0.038moles Br2

since it is a 1:1 ratio moles Cyclohexene=moles 1,2-dibromocyclohexane.

then to determine the limiting reganent i did:
0.026moles cyclohexene (.038moles br2)=0.000988 moles Br2 required for completion.

0.038moles br2 (.026moles)= 0.000988 moles of cyclohexene required for completion...


now...im stuck..

Offline Borek

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Re: Limiting reagent, percent yield...
« Reply #3 on: November 02, 2008, 06:22:11 AM »
then to determine the limiting reganent i did:
0.026moles cyclohexene (.038moles br2)=0.000988 moles Br2 required for completion.

No, that's not the correct way.

Do you know how to read reaction equation?

If 1 mole of cyclohexene reacts with 1 mole of bromine, how many moles of bromine react with 0.026 moles of cyclohexene?
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Offline prncess23

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Re: Limiting reagent, percent yield...*delete me*
« Reply #4 on: November 02, 2008, 03:39:20 PM »
i know how to read an equation.

the answer to your question:
0.026 moles of cyclohexene(1 mole/159.81g)=0.0001627 moles bromine...right???

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