A/S Chemistry Halogens Watch

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supreme
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#1
Report Thread starter 14 years ago
#1
Hi I am really stuck on this question (see attachment) and any help would be greatly appreciated.
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Willa
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Experiment 1:

Displacement reaction:

2NaI + Cl2 -> 2NaCl + I2 (Solid)

Your fumes come from bromine:

2NaBr + Cl2 -> 2NaBr + Br2 (liquid but here it is a vapour)

Experiment 2:

Standard Halide test (however because micture, you cant deduce from colour which halides are present - but because of experiment 1, you know it isnt chlorine)

NaBr + AgNO3 -> NaNO3 + AgBr(solid)
and similar for NaI

The mass question:

the 0.546g at end is due to Iodine (AgBr is soluble in ammonia) so:

0.546/(108+127) = Moles I = 0.0023
(0.902-0.546)/(108+80) = Moles Br = 0.0018

then the masses are: 0.151g Br, 0.295g I
So Percentage composition:

0.151/0.545 * 100 = 27.7%

Iodine: 54.1%


Well i think that's the best i can do...hope it's right
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supreme
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#3
Report Thread starter 14 years ago
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(Original post by Willa)
Experiment 1:

Displacement reaction:

2NaI + Cl2 -> 2NaCl + I2 (Solid)

Your fumes come from bromine:

2NaBr + Cl2 -> 2NaBr + Br2 (liquid but here it is a vapour)

Experiment 2:

Standard Halide test (however because micture, you cant deduce from colour which halides are present - but because of experiment 1, you know it isnt chlorine)

NaBr + AgNO3 -> NaNO3 + AgBr(solid)
and similar for NaI

The mass question:

the 0.546g at end is due to Iodine (AgBr is soluble in ammonia) so:

0.546/(108+127) = Moles I = 0.0023
(0.902-0.546)/(108+80) = Moles Br = 0.0018

then the masses are: 0.151g Br, 0.295g I
So Percentage composition:

0.151/0.545 * 100 = 27.7%

Iodine: 54.1%


Well i think that's the best i can do...hope it's right
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