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Offline portugal

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electrochemistry
« on: 22/08/2007 09:06:31 »
When KBr reacts with conc. H2SO4 some bromine and SO2 are evident as well as the main product (HBr). The number of moles of KBr which reacts with one mole of conc. H2SO4?


 

Offline lightarrow

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« Reply #1 on: 22/08/2007 12:07:16 »
When KBr reacts with conc. H2SO4 some bromine and SO2 are evident as well as the main product (HBr). The number of moles of KBr which reacts with one mole of conc. H2SO4?

In which reaction?

2KBr + H2SO4 --> K2SO4 + 2HBr↑   or:

2KBr + 2H2SO4 --> SO2↑ + Br2↑ + K2SO4 + 2H2O?
 

Offline portugal

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« Reply #2 on: 22/08/2007 13:14:57 »
i will post the full question up ok unchanged:
1. When KBr reacts with conc. H2SO4 some bromine and SO2 are evident as well as the main product (HBr). The number of moles of KBr which reacts with one mole of conc. H2SO4 in this side reaction is:

 a. 1.33 mol

 b. 0.75 mol

 c. 1.00 mol

 d. 2.00 mol

 e. 0.50 mol
 

Offline eric l

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« Reply #3 on: 22/08/2007 14:06:08 »
With the first reaction (only HBr) you have a molar ratio of 2/1
With the second (Br2 and SO2) you have a molar ratio of 1/1
You have both, so the only valid answer is with a value in between or answer A
« Last Edit: 22/08/2007 16:58:14 by eric l »
 

Offline lightarrow

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« Reply #4 on: 22/08/2007 19:16:24 »
i will post the full question up ok unchanged:
1. When KBr reacts with conc. H2SO4 some bromine and SO2 are evident as well as the main product (HBr). The number of moles of KBr which reacts with one mole of conc. H2SO4 in this side reaction is:

 a. 1.33 mol

 b. 0.75 mol

 c. 1.00 mol

 d. 2.00 mol

 e. 0.50 mol
With "this side reaction" it means: the one which forms SO2 and Br2. So you can see from the balanced reaction I wrote that it's 2 moles of KBr and 2 of H2SO4, that means 1 and 1. So the answer is 1 (c.)
 

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« Reply #4 on: 22/08/2007 19:16:24 »

 

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