Author Topic: Chemistry Unit 3b As exam..  (Read 1337 times)

Offline coatseville

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Chemistry Unit 3b As exam..
« on: May 14, 2010, 09:59:24 am »
How did you find it?
24 hours has passed!

Offline Saladin

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Re: Chemistry Unit 3b As exam..
« Reply #1 on: May 14, 2010, 10:14:51 am »
OKish

it was not that easy.

Offline coatseville

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Re: Chemistry Unit 3b As exam..
« Reply #2 on: May 14, 2010, 10:45:53 am »
Yah =(
Question 1 was quite confusing i think..
Oh and what was you % purity?

Offline Saladin

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Re: Chemistry Unit 3b As exam..
« Reply #3 on: May 14, 2010, 10:48:09 am »
I think I got 9.8%.

Offline coatseville

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Re: Chemistry Unit 3b As exam..
« Reply #4 on: May 14, 2010, 11:00:07 am »
Oh okay yeah thats different than mine i got 98.4%

Offline Meticulous

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Re: Chemistry Unit 3b As exam..
« Reply #5 on: May 14, 2010, 11:01:47 am »
Youre right coat. Trust me

Offline coatseville

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Re: Chemistry Unit 3b As exam..
« Reply #6 on: May 14, 2010, 11:07:17 am »
oh thanks :)

Offline M-H

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Re: Chemistry Unit 3b As exam..
« Reply #7 on: May 14, 2010, 11:47:53 am »
good...really good paper:)

Offline Book lover22

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Re: Chemistry Unit 3b As exam..
« Reply #8 on: May 14, 2010, 04:03:31 pm »
Salamzz!

It was a tricky paper like u had 2 think hard! not da typ dat da answer cums wid da flow!
nway only few doubts:

1.wat was da colour change 4 da starch indicator?
2.wat was da test 4 da OH- ion?
**Always keep smiling not because life is full of reasons 2 SMILE but because ur SMILE itself is a reason 4 many others 2 SMILE**

Offline coatseville

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Re: Chemistry Unit 3b As exam..
« Reply #9 on: May 14, 2010, 04:52:23 pm »
The colour change was from blue to colourless
and the OH test is add phosphorus pentachloride and hydrogen chloride (steamy fumes) given off!

Offline Book lover22

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Re: Chemistry Unit 3b As exam..
« Reply #10 on: May 15, 2010, 09:27:36 am »
but isnt dat 4 organic compounds only? :S

i wrote test da solution with red litmus paper it will turn blue...hows dat?

Thanks...
**Always keep smiling not because life is full of reasons 2 SMILE but because ur SMILE itself is a reason 4 many others 2 SMILE**

Offline lupilipid

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Re: Chemistry Unit 3b As exam..
« Reply #11 on: May 15, 2010, 07:36:30 pm »
I got percentage purity as 60% and the starch indicator was iodine (makes sense right?)

Offline coatseville

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Re: Chemistry Unit 3b As exam..
« Reply #12 on: May 15, 2010, 08:23:34 pm »
Im not sure about the OH test group but thats just what I think...
Erm i dont remember the question what did it say about the starch?