Author Topic: Chemistry Help HERE ONLY !!  (Read 107144 times)

Offline kam

  • SF Geek
  • ****
  • Posts: 543
  • Reputation: 30
  • Gender: Female
  • its a real flowa too!
Re: Chemistry Help HERE ONLY !!
« Reply #705 on: May 31, 2009, 07:41:49 pm »
i need help in nov 2004 q7
c)
number of moles of Fe2(SO4)3 = 1/40 or 0.025
number of moles of Fe2 O3 formed = 1/40 or 0.025
mass of iron(III) oxide formed = 0.025 x 160 = 4g
number of moles of SO3 produced = 3/40 or 0.075
volume of sulphur trioxide at r.t.p. = 0.075 x 25
                                               = 1.8dm3
hope it helps



why do u multiply 0.075 by 25?

and can u attatch p3 1999 mark scheme and que paper

+rep



By the way guyz my rep got reduced.... may i know who did it and why????


Offline THEIGBOY

  • SF Immigrant
  • **
  • Posts: 107
  • Reputation: 62
    • www.gaminglagoon.com/signupnowforfreeoffers
Re: Chemistry Help HERE ONLY !!
« Reply #706 on: May 31, 2009, 07:47:17 pm »
argh...sumbudy decreased my rep even more

frget rep man
it dsnt mke a differnc
do u hav the mark scheme?? :-[
go to www.drop.io/theigboy
the password is in ur inbox....
and download the file... i can't upload it here for some reason...

Which year????
i have all marking schemes from 1999 onwards

2003

Offline Priceless

  • SF Master
  • ******
  • Posts: 2071
  • Reputation: 1591
Re: Chemistry Help HERE ONLY !!
« Reply #707 on: May 31, 2009, 08:02:01 pm »
hey igboy der u go...+rep hope it helps u ....lol...gud luck wid ur xams  ;)
Don't say "God I have tooo many problems" but say "Problems I have God!"   Gud Luck 2 all 4 xams. Hope v all du well.....fingers crossed LOL

Offline goin4dakill

  • SF Citizen
  • ***
  • Posts: 157
  • Reputation: 5
Re: Chemistry Help HERE ONLY !!
« Reply #708 on: May 31, 2009, 08:11:47 pm »
HEYYYY GUYSSS!!!!!!!! PLEASE SOMEONE HELP ME?!

Okay, for Organic chemistry, when they ask you for a starch molecule or sugar molecule... My book gives you a very comlex structure that sort of looks like a crab or..a extented hexagon, with OH-O and H..
But the past paper June 2008 marking scheme (its hard to understand what they want us to give) but a simple square with just an -O- on either side! Really would appreciate it guys!

Good luck! By the way when do u guys have ur exam..? I have mine in about 11 hours.. WOOOT!!!!! **cofffeeee time*****************

Offline reishamix

  • SF Geek
  • ****
  • Posts: 345
  • Reputation: 2
Re: Chemistry Help HERE ONLY !!
« Reply #709 on: May 31, 2009, 08:19:37 pm »
HEYYYY GUYSSS!!!!!!!! PLEASE SOMEONE HELP ME?!

Okay, for Organic chemistry, when they ask you for a starch molecule or sugar molecule... My book gives you a very comlex structure that sort of looks like a crab or..a extented hexagon, with OH-O and H..
But the past paper June 2008 marking scheme (its hard to understand what they want us to give) but a simple square with just an -O- on either side! Really would appreciate it guys!

Good luck! By the way when do u guys have ur exam..? I have mine in about 11 hours.. WOOOT!!!!! **cofffeeee time*****************

i guess a -O-[BOX]-O-
is all wht they want..
my tchr told us its simpl fr IGz ..
u gotta do tht fr a levls

Offline goin4dakill

  • SF Citizen
  • ***
  • Posts: 157
  • Reputation: 5
Re: Chemistry Help HERE ONLY !!
« Reply #710 on: May 31, 2009, 08:27:54 pm »
OK thank you!!! Will do then.. Even though they have that in my IGCSE CIE cambridge book..Oh wellz.
Best of luck in ur exam tomoz!!!

Offline SGVaibhav

  • SF Farseer
  • *******
  • Posts: 3013
  • Reputation: 5737
  • Gender: Male
  • Bugatti Veyron 16.4
Re: Chemistry Help HERE ONLY !!
« Reply #711 on: May 31, 2009, 08:30:04 pm »
nice nick goin4dakill

Offline goin4dakill

  • SF Citizen
  • ***
  • Posts: 157
  • Reputation: 5
Re: Chemistry Help HERE ONLY !!
« Reply #712 on: May 31, 2009, 08:31:23 pm »
hahahah arent we all :DDD

Offline X Abdulrahman X

  • SF Farseer
  • *******
  • Posts: 4981
  • Reputation: 3826
  • Gender: Male
Re: Chemistry Help HERE ONLY !!
« Reply #713 on: May 31, 2009, 08:33:29 pm »
peeps this guy is amazing, prob the best chemistry teacher living, i watched about 10 of his vids and they help aloooot esp on organic chemistry, im on a roll now  8)

http://www.youtube.com/user/bannanaiscool
When they talk about me they say I be trippin
What they say about me doesn't make me mad 
I think they hatin cause they see me when I'm rollin
Man I can't help it that they really doin bad  =P

Big cars, Big wheels, Big chains, Big pimpin', Big money, Big Dreams ;-)

Offline heat619

  • Newbie
  • *
  • Posts: 17
  • Reputation: 2
Re: Chemistry Help HERE ONLY !!
« Reply #714 on: May 31, 2009, 08:57:26 pm »
In drawing an alloy, do we draw the different cations with different colors(shade one) or different sizes??? plz reply

Offline Bani

  • SF Immigrant
  • **
  • Posts: 100
  • Reputation: 12
Re: Chemistry Help HERE ONLY !!
« Reply #715 on: May 31, 2009, 08:58:45 pm »
Please help: in October/November 2004, Q6b i) Why do we get -OOC-C6H4-COOCH2CH2O-
Please someone tell me why do we put the O (in bold) after the CH2CH2, shouldn't we just continue with COO bond? Please help

And, Q8c iii) please help how to work out the answer.
Thanks in advance.

Offline Bani

  • SF Immigrant
  • **
  • Posts: 100
  • Reputation: 12
Re: Chemistry Help HERE ONLY !!
« Reply #716 on: May 31, 2009, 09:01:01 pm »
In drawing an alloy, do we draw the different cations with different colors(shade one) or different sizes??? plz reply

Different sizes and shaded I think. But most probably different sizes.

Offline heat619

  • Newbie
  • *
  • Posts: 17
  • Reputation: 2
Re: Chemistry Help HERE ONLY !!
« Reply #717 on: May 31, 2009, 09:13:18 pm »
In drawing an alloy, do we draw the different cations with different colors(shade one) or different sizes??? plz reply

Different sizes and shaded I think. But most probably different sizes.

Thanx +rep!!!!

Offline Bani

  • SF Immigrant
  • **
  • Posts: 100
  • Reputation: 12
Re: Chemistry Help HERE ONLY !!
« Reply #718 on: May 31, 2009, 09:23:33 pm »
Please someone please answer my question....pleaseeee :-[

Offline kam

  • SF Geek
  • ****
  • Posts: 543
  • Reputation: 30
  • Gender: Female
  • its a real flowa too!
Re: Chemistry Help HERE ONLY !!
« Reply #719 on: May 31, 2009, 09:31:22 pm »
Please help: in October/November 2004, Q6b i) Why do we get -OOC-C6H4-COOCH2CH2O-
Please someone tell me why do we put the O (in bold) after the CH2CH2, shouldn't we just continue with COO bond? Please help

And, Q8c iii) please help how to work out the answer.
Thanks in advance.

yeah but didnt u start it with a cooo bond?
 it says cooch2ch2o