« previous next »
Pages: [1] 2   Go Down

Author Topic: chem paper 1 doubt  (Read 3235 times)

Offline zbzbzb25

  • Newbie
  • *
  • Posts: 23
  • Reputation: 5
  • Gender: Female
  • MAY ALLAH SUBHANAWATALA guide us!AMEEN SUMMA AMEEN
chem paper 1 doubt
« on: May 20, 2009, 12:58:57 pm »
ASALAMOALAIKUM WARAHMATULLAHI WABARAKATUHU WAMAGHFIRATUHU
n hi!

which apparatus is most suitable for producing ethanol by fermentation?

A- a conical flask with cotton wool at its mouth containing sugar sol and yeast,not being heated
B-a conical flask with a bung containing sugar sol and yeast,being heated
C-a conical flask with sugar sol and yeast, being heated and no cotton wool or bung with steam escaping
D- a conical flask placed in a tray of ice,the conical flask contains sugar sol and yeast (no bung or cottonwool)

this is qn no. 40 from 0620 november 1999

mark scheme says (A)
but i thnk it shud be (B)

Thanks
JAZA KALLAH KHAIR
ALLAH HAFIZ
FIAMANALLAH
Take care
bye
Logged
'Endow your will ith such power that at every turn of fate God Himself asks of His salve ''What is it that pleases thee?'' '
---Allama Iqbal---
:D

Q80BOY

  • Guest
Re: chem paper 1 doubt
« Reply #1 on: May 20, 2009, 01:04:11 pm »
i agree with u, in the revision guide i use, the diagram shows a bung and an air lock

hope i helped  :)

By the way loved the beginning and ending of ur post  ;)
Logged

Offline annie_angel

  • i m not an artist; just a painter...[ths is so random]
  • SF Geek
  • ****
  • Posts: 475
  • Reputation: 352
  • Gender: Female
  • --->>>Time is nothing but a Precious Enemy<<<---
Re: chem paper 1 doubt
« Reply #2 on: May 20, 2009, 03:04:25 pm »
i think it actuallly is A as if it is heated da yeast would be killed...and b4 da ethanol is made it would be of no use thn...hope this helps
Logged
Dont tell God how BIG your storm is...;tell your storm how BIG your GOD is.^_^

Offline annie_angel

  • i m not an artist; just a painter...[ths is so random]
  • SF Geek
  • ****
  • Posts: 475
  • Reputation: 352
  • Gender: Female
  • --->>>Time is nothing but a Precious Enemy<<<---
Re: chem paper 1 doubt
« Reply #3 on: May 20, 2009, 03:05:59 pm »
Quote from: Q80BOY on May 20, 2009, 01:04:11 pm
i agree with u, in the revision guide i use, the diagram shows a bung and an air lock

hope i helped  :)

By the way loved the beginning and ending of ur post  ;)
bung and an airlock IS needed but if da thing is heated the yeast would die...
Logged
Dont tell God how BIG your storm is...;tell your storm how BIG your GOD is.^_^

Q80BOY

  • Guest
Re: chem paper 1 doubt
« Reply #4 on: May 20, 2009, 03:07:09 pm »
Quote from: annie_angel on May 20, 2009, 03:05:59 pm
Quote from: Q80BOY on May 20, 2009, 01:04:11 pm
i agree with u, in the revision guide i use, the diagram shows a bung and an air lock

hope i helped  :)

By the way loved the beginning and ending of ur post  ;)
bung and an airlock IS needed but if da thing is heated the yeast would die...

ya, so its not A, cause A says that cotton wool is used  :-\
Logged

Offline annie_angel

  • i m not an artist; just a painter...[ths is so random]
  • SF Geek
  • ****
  • Posts: 475
  • Reputation: 352
  • Gender: Female
  • --->>>Time is nothing but a Precious Enemy<<<---
Re: chem paper 1 doubt
« Reply #5 on: May 20, 2009, 03:07:59 pm »
the co2 escapes...
Logged
Dont tell God how BIG your storm is...;tell your storm how BIG your GOD is.^_^

Q80BOY

  • Guest
Re: chem paper 1 doubt
« Reply #6 on: May 20, 2009, 03:09:41 pm »
Quote from: annie_angel on May 20, 2009, 03:07:59 pm
the co2 escapes...

isnt that why we have an airlock ?? for the CO2 to escape?
Logged

Offline annie_angel

  • i m not an artist; just a painter...[ths is so random]
  • SF Geek
  • ****
  • Posts: 475
  • Reputation: 352
  • Gender: Female
  • --->>>Time is nothing but a Precious Enemy<<<---
Re: chem paper 1 doubt
« Reply #7 on: May 20, 2009, 03:11:55 pm »
Quote from: Q80BOY on May 20, 2009, 03:09:41 pm
Quote from: annie_angel on May 20, 2009, 03:07:59 pm
the co2 escapes...

isnt that why we have an airlock ?? for the CO2 to escape?

air LOCK is dere so oxygen doesnt anter or else ethanol would oxidise....or we would get sumthing else [ethanoic acid i think]
 but not ethanol
Logged
Dont tell God how BIG your storm is...;tell your storm how BIG your GOD is.^_^

Offline annie_angel

  • i m not an artist; just a painter...[ths is so random]
  • SF Geek
  • ****
  • Posts: 475
  • Reputation: 352
  • Gender: Female
  • --->>>Time is nothing but a Precious Enemy<<<---
Re: chem paper 1 doubt
« Reply #8 on: May 20, 2009, 03:14:13 pm »
Quote from: annie_angel on May 20, 2009, 03:11:55 pm
Quote from: Q80BOY on May 20, 2009, 03:09:41 pm
Quote from: annie_angel on May 20, 2009, 03:07:59 pm
the co2 escapes...

isnt that why we have an airlock ?? for the CO2 to escape?

air LOCK is dere so oxygen doesnt anter or else ethanol would oxidise....or we would get sumthing else [ethanoic acid i think]
 but not ethanol

enter*
Logged
Dont tell God how BIG your storm is...;tell your storm how BIG your GOD is.^_^

Q80BOY

  • Guest
Re: chem paper 1 doubt
« Reply #9 on: May 20, 2009, 03:14:20 pm »
Quote from: annie_angel on May 20, 2009, 03:11:55 pm
Quote from: Q80BOY on May 20, 2009, 03:09:41 pm
Quote from: annie_angel on May 20, 2009, 03:07:59 pm
the co2 escapes...

isnt that why we have an airlock ?? for the CO2 to escape?

air LOCK is dere so oxygen doesnt anter or else ethanol would oxidise....or we would get sumthing else [ethanoic acid i think]
 but not ethanol

The airlock is used to allow CO2 out and prevent O2 and bacteria entering the fermentation jar, thus allowing anaerobic respiartion to occur.

why is the cotton needed? and where is it placed?
Logged

Offline annie_angel

  • i m not an artist; just a painter...[ths is so random]
  • SF Geek
  • ****
  • Posts: 475
  • Reputation: 352
  • Gender: Female
  • --->>>Time is nothing but a Precious Enemy<<<---
Re: chem paper 1 doubt
« Reply #10 on: May 20, 2009, 04:07:49 pm »
Quote from: Q80BOY on May 20, 2009, 03:14:20 pm
Quote from: annie_angel on May 20, 2009, 03:11:55 pm
Quote from: Q80BOY on May 20, 2009, 03:09:41 pm
Quote from: annie_angel on May 20, 2009, 03:07:59 pm
the co2 escapes...

isnt that why we have an airlock ?? for the CO2 to escape?

air LOCK is dere so oxygen doesnt anter or else ethanol would oxidise....or we would get sumthing else [ethanoic acid i think]
 but not ethanol


The airlock is used to allow CO2 out and prevent O2 and bacteria entering the fermentation jar, thus allowing anaerobic respiartion to occur.

why is the cotton needed? and where is it placed?

A- a conical flask with cotton wool at its mouth containing sugar sol and yeast,not being heated...it says at its mouth...and i think its used for letting co2 escape
Logged
Dont tell God how BIG your storm is...;tell your storm how BIG your GOD is.^_^

Offline MaNa

  • SF Overlord
  • *********
  • Posts: 10219
  • Reputation: 15789
  • Gender: Female
  • InV!ncIbl3!!!!!!
Re: chem paper 1 doubt
« Reply #11 on: May 20, 2009, 04:08:15 pm »
I guess its B bcuz uu doo need to heat the yeast till
30 degree celcius
bcuz below that its inactive n more then that its destroyed
Logged
All ur dreams are made,when you're changed to a mirror and the razor blade!!!

Offline annie_angel

  • i m not an artist; just a painter...[ths is so random]
  • SF Geek
  • ****
  • Posts: 475
  • Reputation: 352
  • Gender: Female
  • --->>>Time is nothing but a Precious Enemy<<<---
Re: chem paper 1 doubt
« Reply #12 on: May 20, 2009, 04:14:57 pm »
but temperature isnt specified
Logged
Dont tell God how BIG your storm is...;tell your storm how BIG your GOD is.^_^

Q80BOY

  • Guest
Re: chem paper 1 doubt
« Reply #13 on: May 20, 2009, 04:18:21 pm »
the question says: which apparatus is most suitable for producing ethanol by fermentation?

my text book and notes say that CO2 escapes from the airlock, no cotton wool is mentioned

are u sure its cotton wool ??  :-\
Logged

Offline MaNa

  • SF Overlord
  • *********
  • Posts: 10219
  • Reputation: 15789
  • Gender: Female
  • InV!ncIbl3!!!!!!
Re: chem paper 1 doubt
« Reply #14 on: May 20, 2009, 04:19:32 pm »
yea
which means its room temperature
w8 it should be 18-20 degree
so yea now it make sence why it is A
with heat
bcuz room temperature is 24 degree
n soo it fermentatrion will carry on
 
Logged
All ur dreams are made,when you're changed to a mirror and the razor blade!!!
Pages: [1] 2   Go Up
« previous next »