Jump to content

  • You cannot start a new topic
  • You cannot reply to this topic

i went over it with chem teacher

someone11

Posted 01 June 2006 - 08:01 PM

I went over it with my chem teacher.


The use of the plastic bag was to CONDENSE WATER VAPOURS
It was addition polymerisation


any other question?

oh and for the record usually in chemistry, especially with questions on experiments, there is usually only one purpose.

ginneswatson

Posted 01 June 2006 - 08:39 PM

You couldn't eleborate could you. Did your teacher say why the bag would need to condense water vapour?

In the old days, the police used this system as a roadside check. The phrase 'could you blow into this bag, sir' became famous. When asked why, the police would say 'because my chips are a bit hot', or so comedians used to tell us.

Anyway, one way of trying to cheat the old breathalyser was to only pretend to blow. The bag is there to stop that. You had to blow until the bag was full.

Not that I was ever breathalysed, you understand huh.gif


d00pyd

Posted 01 June 2006 - 09:36 PM

QUOTE(ginneswatson @ Jun 1 2006, 09:39 PM) View Post

You couldn't eleborate could you. Did your teacher say why the bag would need to condense water vapour?

In the old days, the police used this system as a roadside check. The phrase 'could you blow into this bag, sir' became famous. When asked why, the police would say 'because my chips are a bit hot', or so comedians used to tell us.

Anyway, one way of trying to cheat the old breathalyser was to only pretend to blow. The bag is there to stop that. You had to blow until the bag was full.

Not that I was ever breathalysed, you understand huh.gif


That's the exact reason I gave - to make sure that the person wasn't cheating!

Michael

Posted 01 June 2006 - 09:47 PM

QUOTE(d00pyd @ Jun 1 2006, 10:36 PM) View Post

That's the exact reason I gave - to make sure that the person wasn't cheating!

In the exam, wasn't it a self test kit? Why would they cheat themselves.

ginneswatson

Posted 01 June 2006 - 10:49 PM

Fair enough about the cheating. rolleyes.gif

But I still feel you would want to have a minimum volume of breath going through the tube.


Michael

Posted 01 June 2006 - 10:55 PM

QUOTE(ginneswatson @ Jun 1 2006, 11:49 PM) View Post

Fair enough about the cheating. rolleyes.gif

But I still feel you would want to have a minimum volume of breath going through the tube.

Yeah you would otherwise the reading would be completely inaccurate. Personally I think there will be various answers to that question.

d00pyd

Posted 02 June 2006 - 08:22 AM

That's why I put the exclamation mark - I agree it was a ridculous answer!

someone11

Posted 02 June 2006 - 02:39 PM

nonono. not to disallow cheaters. It was to make the test more reliable, its harder to test a gas than a liquid.

Nathan

Posted 02 June 2006 - 04:05 PM

QUOTE(someone11 @ Jun 2 2006, 03:39 PM) View Post

nonono. not to disallow cheaters. It was to make the test more reliable, its harder to test a gas than a liquid.


I would say no to that too....i would say that it was to get the same volume each time and therefore the test is valid.

ginneswatson

Posted 02 June 2006 - 05:51 PM

I've maybe confused things here. When I was talking about 'cheating' I was only talking about the old breathalyser as used by the police. I wasn't suggesting that that was a reason for having the bag in the context of the exam question. ph34r.gif

For the exam question, I think, the bag ensures that a decent volume of air has been blown over the crystals to make it fair, reliable, repeatable, consistent, .......... take your choice. rolleyes.gif


sarmad

Posted 02 June 2006 - 09:09 PM

QUOTE(ginneswatson @ Jun 2 2006, 06:51 PM) View Post

I've maybe confused things here. When I was talking about 'cheating' I was only talking about the old breathalyser as used by the police. I wasn't suggesting that that was a reason for having the bag in the context of the exam question. ph34r.gif

For the exam question, I think, the bag ensures that a decent volume of air has been blown over the crystals to make it fair, reliable, repeatable, consistent, .......... take your choice. rolleyes.gif

i wrote so that the air mixture doesnt escape, also that it has been oxidised resulting in it forming an acid and therefore can not be allowed to escape as it could be dangerous. Is this a wrong answer???

ice_illusion

Posted 02 June 2006 - 10:33 PM

QUOTE(sarmad @ Jun 2 2006, 10:09 PM) View Post

QUOTE(ginneswatson @ Jun 2 2006, 06:51 PM) View Post

I've maybe confused things here. When I was talking about 'cheating' I was only talking about the old breathalyser as used by the police. I wasn't suggesting that that was a reason for having the bag in the context of the exam question. ph34r.gif

For the exam question, I think, the bag ensures that a decent volume of air has been blown over the crystals to make it fair, reliable, repeatable, consistent, .......... take your choice. rolleyes.gif

i wrote so that the air mixture doesnt escape, also that it has been oxidised resulting in it forming an acid and therefore can not be allowed to escape as it could be dangerous. Is this a wrong answer???

Theres probably going to be a few million answers accepted for that one. Not allowing the air mixture to escape could be ok.

someone11

Posted 07 June 2006 - 05:32 PM

who cares actually. it was only worth 1% of your mark. enjoy your summer yall

  • You cannot start a new topic
  • You cannot reply to this topic